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Scientific  American 


Home  Mechanics 

For  Amateurs 


BY 

GEORGE  M.  HOPKINS 

Author  of  ^^Experimental  Science'' 


Munn  & Co.,  Publishers 

SCIENTIFIC  AMERICAN  OFFICE 


NEW  YORK,  1903 


Copyrignt,  190J,  by  Munn  & Co. 

All  rights  reserved. 

Entered  at  Stationers’  Hall,  London,  P'ngland* 


Pkkss  oh  Andrew  H.  Khli-ogc; 
Niiw  York,  U.  S,  A. 


PREFACE 


SPECIAL  INTEREST  alwaj’s  attaches  to  a i^ost- 
IniiiKois  work.  It  is  not  always,  however,  that 
a work  of  this  character  possesses  ecpial  merit 
witli  one  entirely  completed  before  the  death  of  the 
antlior.  As  a rule  such  works  have  not  had  the  ad- 
vantage of  the  final  perusal  and  correction  by  the 
author.  Such  has  not,  however,  been  the  case  in  tlie 
present  instance,  for  the  following  work  by  the  late 
George  M.  Hopkins,  was  completed  before  his  death. 
There  is  no  doubt,  however,  that  this  volume  Avill  come 
as  a surprise  to  thousands  who  have  closely  followed 
Mr.  Hopkins’  work,  and  who  have  enjoyed  making 
— tlie  many  experiments  descril)ed  by  him.  The  present 
volume  contains  much  matter  which  has  never  before 
appeared  in  iirint,  and  some  articles  which  have  al- 
ready been  piiblished  in  the  Scientific  American.  The 
object  of  the  work  is  to  furnish  food  for  thought  to  the 
amateur,  and  to  give  him  suggestions  whereby  he  may 
pass  nianj’  pleasant  hours  in  his  work-sliop.  Mr.  Hop- 
kins was  an  expert  mechanic.  One  of  his  chief  pleas- 
ures was  to  make  experiments  at  his  home  in  his  well- 
equipped  work-shop  and  laboratory,  and  the  work 
described  in  the  present  volume  is  nearly  all  the  result 
of  experiments  made  by  liim  during  such  “idle”  hours. 
It  has  been  tlie  intent  of  the  autlior  to  make  the  present 


rUKFACE. 


work  as  sug.c;estive  as  possible.  No  ootii])lieate(l  aje 
paratus  is  required  in  carrying  out  tlie  (“xperiuieuts 
described.  Any  one  with  ordinary  mechanical  inge- 
nuity and  having  a lathe  and  a few  tools  ca!i  make  most 
of  the  expei'iments  described  in  these  pages. 

A few  articb'S  by  other  authors  have  Ix'en  included 
as  they  are  germane  to  the  sco})e  of  the  book.  It  is 
hoped  that  “Home  ^lechanics  for  Amateurs”  will  prove 
heliifnl  to  as  many  thousands  as  has  “Experimental 
Science.” 


Table  oe  Contents 


PART  1. 

Wood-Working 

An  Inexpensive  Turning  Lathe.  Turning.  Wood-Working  on  a 
Lathe.  Work  Bench  and  Tools  for  Woodwork.  Whittling. 
Different  Shapes  of  Saw  Teeth  and  the  Way  they  Cut.  A 
Wrinkle  in  Sawing.  Wood  Carving  1 


PART  11. 

How  TO  Make  Household  Ornaments 

Home-made  Grilles  hnd  Gratings.  Wall  Ornaments.  Pseudo- 
Ceramics.  Imitation  of  Majolica.  Stained  Glass  and  Ob- 
jects of  Wire  Cloth.  Japanese  Portiere  or  Curtain. 
Repousse.  An  Easy  Method  of  Producing  Bas-reliefs. 
Ornamental  Iron  Work  for  Amateurs.  Some  Things  in 
Wire.  Some  Things  in  Burnished  Brass.  Forming  Plaster 
Objects  31 


PART  III. 

Metal-Working 

Sawing  Metals.  Soldering.  Grinding  and  Polishing.  Silver 
Work.  Metal  Foot  Lathe.  Drills  and  Drilling.  Centering 
and  Steadying.  Chucking.  Metal  Turning.  Chasing  and 
Knurling.  Rotary  Cutters.  Easily  made  Slide  Rest.  In- 
dex Plates  for  Gear  Cutting.  Gear  Cutting  Apparatus. 
Hints  on  Model  Making.  Metal  Spinning  89 


of  coN'i'FX'rs 

PART  IV. 

Model  Engines  and  Boilehs 

A Home-made  Steam  Engine.  A Safe  Way  of  Running  a Small 
Engine.  A Miniature  Caloric  Engine.  An  Inexpensive 
Water  Motor  1G9 


PART  V. 

Meteorology 

Self-Recording  Instruments.  What  may  be  learned  by  the  Use 
of  the  Meteorological  Instruments.  A Weather  Vane. 
Wind  Pressure  Gauge.  Rain  Gauge.  A Metallic  Ther- 
mometer. A Simple  Hygroscope.  A Mercurial  Barometer.  187 


PART  VI. 

Telescopes  and  Microscopes 

How  to  make  a Telescope.  The  Microscope 207 


PART  VII. 

Electricity 

A Practical  Primary  Battery.  Electric  Lighting  for  Amateurs. 

The  Electric  Chime.  Home-made  Electric  Night  Lamp. 

An  Electrical  Cabinet.  Simple  Electric  Motor.  Small 
lOlectric  Motor  for  Amateurs.  How  to  make  a Sewing 
Machine  Motor  without  Castings.  A Design  for  an  Electric 
Launch  Motor.  How  to  make  an  Edison  Dynamo  and 
Motor.  The  Utilization  of  110  Volt  Electric  Circuits  for 
Small  thirnac.e  Work.  Recording  Telegraiih  for  Amateurs. 

How  to  make  a Telei)hone  227 


PART  I. 

WOOD- WORKING 

AN  INEXPENSIVE  TUKNING  LATHE 

The  boy  wlio  has  a turning  lathe  can  readily 
make  many  things  which  he  might  not  feel 
disposed  to  buy ; for  example,  he  can  make  tops, 
ninepins,  and  ornamental  and  useful  objects 
without  much  trouble  and  with  very  little  expense. 
The  ancient  lathe  consisted  of  two  conical  points,  sup- 
ported in  position  by  suitable  standards,  and  the  work 
to  be  done  was  whirled  on  these  points  by  means  of  a 
strong  cord  wrapped  once  around  the  stick  to  be  turned, 
with  the  upper  end  attached  to  a spring  pole  and 
the  lower  end  seciired  to  a treadle.  The  lathe  we  are 
about  to  describe  is  one  remove  from  this  primitive 
lathe  of  the  olden  time.  It  has  the  two  standards  with 
points  or  dead  centers,  as  they  would  be  called  by  ma- 
chinists, but  one  of  the  points  projects  far  enough  from 
the  standard  to  receive  a hard  wood  pulley,  having 
inserted  in  its  side,  at  diametrically  opposite  points, 
two  spurs,  which  enter  the  end  of  the  piece  of  wood 
to  be  turned,  so  that  Avhen  the  pulley  is  revolved  by 
a belt,  the  wood  will  be  turned  on  the  centers. 

This  lathe  is  made  almost  entirely  from  strips  of 
hard  wood,  1 inch  thick  and  2^  inches  wide.  These 
strips  can  be  easily  furnished  by  any  carpenter,  cabinet 
maker  or  wagon  maker,  and  an  old  table  may  be  used 
for  the  frame. 

The  bed-piece  is  made  of  two  such  strips,  2 feet  long, 
and  a block  of  the  same  material,  1 inch  square  and  2 

[IJ 


2 


HOME  IIECIIAXK^S  FOE  AMATEIJI^S 


inches  long,  at  one  (aid  is  plai'ed  betwecai  the  strips 
and  lield  in  ])la(‘(‘  by  wood  scr(‘ws.  A piiaa^  of  tliick 
paper  is  placanl  between  tlie  lihx'k  and  one  of  tli(‘  strijis, 


Fig.  1.  An  Easily  Constructed  Wood  Lathe. 


to  niak(*  1h(‘  space*  lx*!  w(*(*ii  the  strips  a little  wider  than 
th(*  I liickiK'SS  of  i Ik*  lilock. 

n'o  (*acl)  (*ikI  of  I Ik*  bed  is  S(*cni'ed  a foof^  (‘onsistini2^ 
of  a pi(*c(*  of  11k*  saiiK*  si  rip,  (>  iiK'lK‘S  lon<4’.  Tln^se  aiv 
s(*(‘iir(*d  by  w'ood  s(  r(*\\'s  passing  iipwaixl  tIiroui»li  holes 


HOME  MECHANICS  FOR  AMATEURS 


3 


in  the  lower  edge  of  the  foot,  the  holes  being  deeply 
countersunk  to  let  in  the  heads  of  the  screws. 

The  head  stock  and  tail  stock  are  nearly  alike,  in 
so  far  as  the  wood  work  is  concerned.  Each  is  formed 
of  three  pieces  of  the  strip  from  which  the  bed  is 
made.  To  opposite  sides  of  a central  piece,  7^  inches 
long,  are  secured  side  pieces  4 inches  long,  by  means 
of  screws.  Tliese  side  pieces  must  of  course  be  square 
on  the  end  so  that  they  will  set  squarely  on  the  bed 
when  the  projecting  end  of  the  central  piece  is  inserted 


Fig.  2.  Work  in  the  Lathe. 


in  the  slot  of  the  bed.  The  lower  end  of  the  center  piece 
is  mortised  to  receive  a Avooden  key  or  Avedge,  Avhich 
clamps  the  tail  stock  to  the  bed.  In  the  tail  stock,  4 
inch  from  the  top,  is  bored  a hole  in  Avhich  is  inserted 
a large  Avood  screAv,  the  point  of  Avhich  is  filed  conically, 
as  shoAvn.  In  the  head  stock  is  also  bored  a hole 
corresponding  Avith  that  of  the  tail  stock,  to  receive  a 
large  Avood  screAV,  ^ or  5-16  inch  in  diameter.  The  head 
of  this  screAv  is  cut  off,  and  the  head  end  is  filed  off 
conically.  This  point  shonld  project  about  an  inch 
from  the  head  stock,  and  to  the  plain,  smooth  pro- 


4 


HOME  MECHANTCS  EOli  AMATEURS 


jeotiug  part  of  tlie  screw  is  fitted  a small  jrrooved 
pulley  about  iuclies  iu  diam(‘t(“r  at  the  bottom  of 
the  groove.  The  ])ulley  should  be  of  Habbitt  metal 
or  type  metal.  Ju  the  side  of  the  ])ulley,  about  | 
inch  from  the  hole,  are  inserted  two  small  screws,  about 
f inch  long,  which  are  allowed  to  ])i‘oject;  these*  screws 
are  filed  to  form  chisel-edged  sjeurs  for  driving  the 
work  in  the  lathe.  The  jeoints  should  project  as  far 
as  the  ]K)int  of  the  conical  end  of  the  lai'ge  scr<>w. 

The  lower  end  of  the  head  stock — which  is  about  2} 
inches  long — is  inserted  between  the  strips  forming 
the  bed,  and  fastened  with  screws;  a piece  of  pa])er 
being  inserted  to  increase  the  space  between  the  strips, 
so  that  the  tail  stock  can  be  moved  easily. 

The  wood  to  be  turned  has  a small  hole^ — say,  ^ inch 
— bored  in  the  center  at  each  end,  and  is  placed  be- 
tween the  centers;  the  tail  stock  having  been  clamped 
in  the  proper  position,  the  tail  screw  is  turned  with 
a screw  driver  until  it  is  forced  a short  distance  into 
the  end  of  the  stick.  Then  the  stick  is  driven  for- 
ward on  to  the  center,  and  spurs  of  the  head  stock,  and 
the  screw  in  the  tail  stock  is  turned  so  as  to  hold  the 
stick,  but  not  enough  to  create  friction.  A drop  of  oil 
should  be  put  on  each  center,  and  the  pulley  should 
be  oiled. 

The  rest  on  which  the  gouge  or  chisel  is  placed  while 
the  turning  is  being  done  consists  of  a piece  of  the 
wood(‘n  strip  with  a slot  in  it  to  allow  a 5-inch  car- 
riage bolt  to  pass  through.  This  bolt  extends  through 
the  slot  of  the  bed,  and  through  a block  or  washer  be- 
low. A wing  nut  is  ])lac(“d  on  the  bolt  so  that  the  rest 
may  be  clamjx'd  in  any  desired  i)osilion.  To  the  end  of 
the  slotted  piece  is  secured  a shoi*t  ])iece  of  the  wooden 


HOME  MECHANICS  FOE  AMATEUES 


6 


strip  by  two  screws  passing  through  the  slotted  piece 
and  into  the  wood.  The  wooden  rest  should  be  beveled 
as  shown. 

It  ninst  be  frankly  admitted  this  lathe  is  not  an 
elegant  machine  to  look  at,  but  it  is  capable  of  turning 
out  quite  reputable  small  work. 

Having  made  the  lathe,  it  will  be  necessary  to  pro- 
vide some  means  to  drive  it.  In  almost  every  city  and 
town  may  be  found  old  sewing  machine  tables,  which 
have  been  taken  in  trade  as  old  iron.  One  of  these  can 
be  bought  cheaply,  and  when  the  treadle  is  turned 
around  and  a round  leather  belt  applied  to  the  lathe 
pulley  and  the  sewing  machine  wheel,  the  arrangement 
is  complete. 

Some  one  may  be  found  good  enough  to  loan  a sew- 
ing table  for  the  purpose.  In  this  case,  an  assistant 
will  be  obliged  to  work  the  treadle  while  the  turning 
is  being  done. 

As  the  flywheel  should  be  heavy,  not  less  than  20 
pounds,  and  as  it  should  be  about  20  inches  in  diameter 
to  secure  the  desired  speed,  it  is  perhaps  better  to  fit 
up  the  lathe  with  a wheel  and  table  better  adapted 
to  it  than  a sewing  machine  wheel  and  table  would  be. 

The  lathe  shoAvn  in  the  illustration  is  mounted  on  a 
common  kitchen  table  of  the  smallest  size.  In  this 
case,  an  old  wheel  is  selected  at  the  junk  shop;  one 
with  a groove  in  the  edge  is  to  be  preferred,  but  a flat 
rim  will  answer.  The  one  here  shown  has  a flat  face 
and  is  provided  Avith  a shaft,  a crank  and  standards. 
The  standards  are  inverted  and  fastened  with  screws 
to  the  under  side  of  the  table  top. 

A strip  of  board  extending  lengtlnvise  of  the  table 
is  attached  to  the  rear  legs  with  screws,  and  the  piece 


6 


MVTUANICH  FOR  A^yiATFTIRS 


of  hoard  foriniiiiij  tlu‘  ti'(‘adl(*  is  to  it  in  position 

to  rcM'oive  tlie  S(*rew  wlii(di  pass(‘s  tliroipj^li  tin*  !ow(‘r 
end  of  tlie  pitman  rod  or  eonn(‘etin<»:  rod,  tli(‘  n])p(*r 
end  beins’  apertnred  to  T'(H*eiv(‘  tli(‘  ('raidv  ])in.  A round 
leatlier  belt  is  used  in  tliis  (*ase. 

Tlie  tools  for  tnrnin£>’  are  not  wry  (^x})(msiv(‘ ; with 
two  o’oiioes  and  one  or  two  flat  (diisels  a great  varied j 
of  work  may  be  done. 


TUlINTXa 

There  is  no  secret  in  turning.  Tt  requires  a great 
deal  of  practice  to  bee-ome  an  expert,  bnt  beyond  ac()nir- 
ing  the  first  principles  nothing  further  than  practice 
is  required.  When  reducing  a piece  of  wood  to  the 


Fig.  3.  Lathe  Turning  Tools. 


d(^sir(Ml  approximate^  siz(‘,  tln^  gouge  is  held  on  the 
ri'st  w ith  its  handl(‘-(‘nd  ineliiKMl  downward  at  an  angle 
of  about  ()0°  wilh  fin*  borizonlal,  lln^  re^st  b(‘ing  near 
the  work,  and  tin*  gonge  is  inove^d  ba(*k  and  forth  on  the* 


HOME  MECHANICS  FOE  AMATEUKS 


rest,  taking  off  a slight  shaving  each  time  it  is  moved. 
The  handle  is  held  in  the  right  hand,  while  the  blade 
of  the  gouge  is  held  in  the  left  hand,  with  the  thumb 
pressing  on  the  concave  side.  If  a plain  cylinder  is 
required  it  may  be  made  by  using  the  flat  chisel,  lay- 
ing the  beveled  edge  on  the  work  in  such  a manner  as 
to  produce  a drawing  cut  as  the  wood  passes  the  edge. 
If  the  work  is  to  be  cut  into  at  right  angles  or  at  any 
other  angle,  the  chisel  is  placed  on  its  edge  on  the  rest 
and  held  firmly  while  moving  it  forward. 

In  cutting  concave  forms  the  gouge  is  made  to  make 
a drawing  cut  by  placing  it  partly  on  its  edge  on  the 
rest.  It  will  be  found  necessary  in  either  of  these 
cases  to  hold  the  tool  very  firmly  on  the  rest  to  pre- 
vent the  edge  from  drawing  itself  forward  on  the  wood 
and  spoiling  the  work.  By  practice  the  art  of  wood- 
turning  can  be  readily  acquired  even  by  the  use  of 
the  ^‘Simple  Lathe.” 

For  hard  wood  and  ivory  a different  class  of  tools 
is  required.  The  chisels  are  all  flat,  not  oblique;  some 
of  them  have  edges  that  are  square  across;  some  have 
V-shaped  points  and  others  are  round-nosed.  For 
under-cuts  and  odd  work,  special  tools  are  bent  at 
different  angles.  Flat  work,  such  as  rosettes,  etc.,  is 
chucked  upon  the  face  plate,  or  attached  with  screws 
to  a board  fixed  to  the  face  plate. 

In  finishing  work  the  use  of  fine  sandpaper  is  admis- 
sible, but  it  never  should  be  used  to  correct  poor  turn- 
ing. Wood  work,  when  smoothed  a little  with  fine 
sandpaper,  may  be  finished  by  applying  to  it  with  a 
cloth  a mixture  of  shellac  varnish  and  linseed  oil,  in 
proportion  of  about  one  part  of  oil  to  two  of  shellac. 
Only  a little  is  applied  to  the  cloth  at  one  time,  the  pol- 


8 


HOME  MECHANICS  FOE  AMATEHRS 


ish  beiiifi:  well  shaken  before  it  is  a])])li(‘<l.  The  work  in 
the  lathe  is  rapidly  revolved  nntil  it  is  hri<,ditly  polished 
and  the  shellac  varnish  is  hard.  If  desired,  the  work 
may  he  stained  before  it  is  polished.  The  stains  are 
readily  obtainable,  and  are  described  in  the  “Scientific 
American  Cyclopedia  of  Receipts,  Notes  and  (^neries.” 

WOOD-WORKING  ON  A LATHE 

It  is  not  the  intention  of  the  writer  to  enter  largely 
into  the  subject  of  wood-working,  hnt  simply  to  sng- 
cest  a few  handv  attachments  to  the  foot  lathe  which 
will  greatly  facilitate  the  operations  of  the  amateur 


Fig.  4.  Saw  Table. 


wood  worker,  and  will  be  found  very  useful  by  almost 
any  one  workiiii^  in  wood.  It  is  not  an  easy  matter 
to  split  even  thin  lumber  into  strips  of  uniform  width 
by  ni(‘ans  of  a handsaw,  but  by  using  the  eireular  saw 
atlachimmt,  shown  in  hhg.  4,  the  operation  becomes 
rapid  and  (^asy,  and  tln^  stuff  may  be  sawed  or  slit  at 
any  d(*sir(*d  angh^  or  b(‘\(^l.  The  atta(‘hm(ait  consists 
of  a saw  mandi‘(4  of  lb(‘  usual  foi'in,  and  a wood(ui  table 
supporl(*d  by  a I'ight  angl(*d  pie(*e,  A,  of  round  iron 


HOME  MECHANICS  FOR  AMATEURS 


9 


fitted  to  the  toolpost  and  clamped  by  a wooden  cleat, 
B,  which  is  secnred  to  the  nnder  side  of  the  table, 
split  from  the  aperture  to  one  end,  and  provided  with 
a thumbscrew  for  drawing  the  parts  together.  By 
means  of  this  arrangement  the  table  may  be  inclined 
to  a limited  angle  in  either  direction,  the  slot  through 
which  the  saw  projects  being  enlarged  below  to  admit 
of  this  adjustment. 

The  back  of  the  table  is  steadied  by  a screw  which 
rests  upon  the  back  end  of  the  tool  rest  support,  and 
enters  a block  attached  to  the  under  side  of  the  table. 
The  gauge  at  the  top  of  the  table  is  used  in  slitting  and 
for  other  purposes  which  will  be  presently  mentioned, 
and  it  is  adjusted  by  aid  of  lines  made  across  the  table 
parallel  with  the  saw. 


Fig.  5.  Fig.  6.  Fig.  7. 


Saw  between  beveled  Washers.  Moulding  Knives. 

For  the  purpose  of  cross-cutting  or  cutting  on  a 
bevel  a thin  sliding  table  is  fitted  to  slide  upon  the 
main  table,  and  is  provided  Avith  a gauge  Avhich  is 
capable  of  being  adjusted  at  any  desired  angle.  For 
cutting  slots  for  panels,  etc.,  thick  saAvs  may  be  used, 
or  the  saAv  may  be  made  to  Avabble  by  placing  it  be- 
tAveen  tAvo  beveled  washers,  as  shoAvu  in  Fig.  5. 

The  saAV  table  has  an  inserted  portion,  C,  held  in 
place  by  two  screws  Avhich  may  be  removed  Avhen  it 
is  desired  to  use  the  saAV  mandrel  for  carrying  a sticker 
head  for  planing  small  strips  of  moulding  or  reeding. 


10 


mmK  AIKCMIANK^S  FOR  AAIATKURS 


(Fi<>s.  ()  and  7.)  Tlu‘  li(‘a(I  for  lioldiiii;  th(*  moulding]; 
knives  is  b(\st  made  of  i>()od  toui»li  brass  or  st(‘am  iindal. 
Tlie  knives  ean  be  made  of  <»()od  saw  steel  about  J ineh 
tliiek.  Tliey  may  be  RRmI  into  sliape  and  aft(‘rward 
tempercHl.  Tlnw  air  slott(‘d  and  lield  to  tlieir  ])laees 
on  tlie  bead  by  means  of  -|-in(‘li  maeliine  screws.  It  is 
not  absolutely  lUH'essaiw  to  ns(^  two  knives,  but  when 
only  one  is  employed  a (‘onntca'balam'e  should  be  fas- 
tened to  the  head  in  ])la(‘e  of  the  othei*.  All  kinds  of 
monldino-,  beadin<»',  tonf»nini>  and  i»i'ooviniL»‘  may  be  done 
with  this  attachment,  the  <>ani»*e  being  used  to  guide  the 


edge  of  the  stuff.  If  the  boards  are  too  thin  to  sup- 
]jort  themselves  against  the  action  of  the  knives  they 
must  be  backed  up  by  a thick  strip  of  wood  planed 
true.  The  speed  for  this  cutter  head  should  be  as  great 
as  jiossible. 

Fdg.  8 shows  an  attachment  to  be  used  in  connection 
with  the  cutter  head  and  saw  table  for  cutting  straight, 
s[)iral  or  irrc^gular  tintes  on  turned  work.  It  consists 
of  a bar,  I),  (*arrying  a (*entral  fix(‘d  arm,  and  at  either 
(md  an  adjustable  arm,  the  jinrjiose  of  the  latter  being 
lo  adapt  lh(*  d(*vi(*(*  to  work  of  dilfia'cmt  haigths.  The 
arm  [)roj(‘cting  from  th(‘  (*(ml(‘r  of  the  bar,  1),  sup- 


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11 


ports  an  arbor  having  at  one  end  a socket  for  receiving 
tlie  twisted  iron  bar,  E,  and  at  the  other  end  a center 
and  a short  Anger  or  pin.  A metal  disk  having  three 
spurs,  a central  aperture  and  a series  of  holes  equally 
distant  from  the  center  and  from  each  other,  is  at- 
tached by  its  spitrs  to  the  end  of  the  cylinder  to  be 
Anted,  and  the  center  of  the  arbor  in  the  arm,  D,  enters 
the  central  hole  in  the  disk  while  its  Anger  enters 


Fig.  9.  Pig.  10. 

Moulding  Irregular  Work. 


one  of  the  other  holes.  The  opposite  end  of  the  cylin- 
der is  supported  by  a center  screiv.  A fork  attached 
to  the  back  of  the  table  embraces  the  twisted  iron,  E, 
so  that  as  tlie  wooden  cylinder  is  moved  diagonally 
over  tlie  cutter  it  is  slowly  rotated,  making  a spiral 
cut.  After  the  Arst  cut  is  made  the  Anger  of  the  arbor 
is  removed  from  the  disk  and  placed  in  an  adjoining 
hole,  when  the  second  cut  is  made,  and  so  on. 


12 


HOME  MECHANICS  FOR  AT\rA^J^EUl?S 


Figs.  9 and  10  sliow  a convoniont  and  (‘asily  made 
attaelinient  for  monlding  tlu^  (Mlges  of  irr(\gnlar  work, 
snrli  as  brackets,  frames,  parts  of  ])atterns,  etc.  It 
consists  of  a brass  franu^,  sn])])orting  a small  man- 
drel turning  at  the  top  in  a (‘oni(‘al  bearing  in  the 
frame,  and  at  tlie  bottom  upon  a eoni(*al  S(*rew.  A very 
small  grooved  pnlley  is  fastemMl  to  the  niandr(d  and 
surrounded  by  a rubber  ring  wliieh  bears  against  the 
face  plate  of  the  lathe,  as  shown  in  the  engraving.  The 
frame,  is  let  into  a wooden  table  supported  by  an 


iron  rod  which  is  received  by  the  tool  rest  holder  of 
th(^  lathe.  The  cntter,  (t,  is  made  by  turning  upon  a 
])\oco  of  ste(^l  th(^  reverse  of  the  required  monlding,  and 
slotting  it  transversely  to  form  cutting  edges.  The 
shank  of  th(^  (‘iittcn*  is  fitted  to  a hole  in  the  mandrel  and 
S(*cured  in  plac(‘  by  a small  set  s(*i'(nv.  The  (Mlge  of  the 
v'ork  is  j)(*rmi<l(‘d  to  b(‘ar  against  the  shank  of  the  (ait- 
t(n*.  Should  lh(‘  fa(‘(‘  y)lat(^  of  the  lathe  b(‘  too  small  to 
give*  lh(*  r(Mpiir(*d  sp(‘(*d,  a wood(‘n  disk  may  be  attached 
to  il  by  m(‘ans  of  scr(*ws  and  (nrn(‘d  off. 


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13 


Figs.  11,  12,  and  13  represent  a cheaply  and  easily 
made  scroll  saw  attachment  for  the  foot  lathe.  It  is 
made  entirely  of  wood  and  is  practically  noiseless.  The 
board,  II,  snpports  two  nprights,  I,  between  which  is 
pivoted  the  arm,  J,  whose  nnder  side  is  parallel  with 
the  edge  of  the  hoard.  A block  is  placed  between  the 
nprights,  I,  to  limit  the  downward  movement  of  the 
arm,  and  the  arm  is  clamped  by  a bolt  which  passes 
throngh  it  and  through  the  two  nprights  and  is  pro- 
vided with  a Aving  nut. 

A wooden  table,  secured  to  the  upper  edge  of  the 
board,  H,  is  perforated  to  allow  the  saw  to  pass 


Fig.  13. 

through,  and  is  provided  with  an  inserted  hard- 
wood strip  Avhich  supports  the  back  of  the  saw, 
and  which  may  be  moved  forward  from  time  to 
time  and  cut  off  as  it  becomes  worn.  The  upper 
guide  of  the  saiv  consists  of  a round  piece  of 
hard  wood  inserted  in  a hole  bored  in  the  end 
of  the  arm,  J.  The  upper  end  of  the  saw  is  secured  in  a 
small  steel  clamp  pivoted  in  a slot  in  the  end  of  a 
wooden  spring  secured  to  the  top  of  the  arm,  J,  and  the 
lower  end  of  the  saw  is  secured  in  a similar  clamp 
pivoted  to  the  end  of  the  wooden  spring,  K.  Fig.  13 
is  an  enlarged  view  showing  the  construction  of  clamp. 

The  relation  of  the  spring,  K,  to  the  board,  H,  and  to 


14 


IlOMI^]  JMKCIIAXK^S  KOK  A.MATKIJUS 


the  otlier  part  is  shown  in  12.  It  is  atta(*li(Ml  to  tin* 
side  of  tlie  hoard  and  is  i>ressed  n])ward  ))y  an  adjust- 
ing screw  near  its  fixed  end. 

The  saw  is  drivcni  l)y  a wooden  (‘('centric*  ])la('(‘d  on  tin* 
saw  inandrel  sliown  in  fXgs.  -1  and  A,  and  the  sj)ring,  K, 
always  press(‘d  ni)war(l  against  th(‘  (‘('('(‘iitric'  hy  its  own 
elasticity,  and  it  is  also  drawn  in  an  n])ward  direction 
hy  the  npp(‘r  spiang.  Tin's  arrang(‘inent  insnr(‘s  a (‘on- 
tinnons  contact  hetween  tli(‘  S])ring,  K,  and  tli(‘  (‘ccen- 
tric,  and  ('onsecjnently  avoids  n()is(‘.  Tlie  fric'tion  snr- 
fa('(‘s  of  tlie  (‘('('(‘iitric*  and  si)ring  may  he  Inhric'ated 
with  tallow  and  jilnmhago.  The  eccentric  may,  with 
a(lvantag(‘,  h(‘  made  of  metal. 

Th(‘  tension  of  the  u])])er  s])ring  may  he  varied  hy 
})ntting  niidcm  it  blocks  of  differ(‘nt  heights,  or  the 
s('rew  which  holds  the  hack  end  may  he  used  for  this 
jmrpose. 

The  saw  is  attached  to  the  lathe  hy  means  of  an  iron 
hent  twice  at  right  angles,  attached  to  the  hoard,  H,  and 
fitted  to  the  tool  rest  support.  The  rear  end  of  the  saw- 
ing apparatus  may  he  supported  hy  a hrace  running  to 
th(‘  lower  part  of  the  lathe  or  to  the  floor. 

Th(‘  simple  attachments  above  described  will  enable 
th(‘  jiosscssor  to  make  many  small  articles  of  furniture 
w hich  h(‘  would  not  undertake  without  them,  and  for 
making  models  of  small  patterns  they  are  almost  in- 
valnahl(‘. 


WORK  RF.NCII  AND  TOOLS  FOK  WOODAYORK 

Th(^  first  thing  r(‘(piir(‘(l  hy  th(‘  amatcmr  workman  is 
a hmich  with  a f(‘W  tools  for  wood  working.  Tli(‘  heiu'h 
n(*(*(l  not  n(*c(*ssarily  lx*  a long  and  heavy  structure  like 


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15 


a carpenter’s  bench,  as  the  work  to  be  done  by  the  ama- 
teur is  mostly  small,  requiring  but  little  material  and 
small  room.  A table  like  that  shown  in  connection 
with  the  simple  lathe  will  answer,  or  the  rear  portion 
of  the  lathe  table  may  be  used  as  a bench.  A small 
wooden  vise  is  secured  to  the  side  of  the  table  near  the 
left  hand  end,  and  in  the  top  of  the  table  is  inserted  a 
common  flat  headed  wood  screw,  which  may  be  screwed 
down  even  with  the  top  of  the  table,  or  raised  ^ or  ^ 
inch,  as  the  work  may  require.  This  screw  takes  the 
place  of  the  usual  bench  dog,  and  holds  the  end  of  a 
piece  of  wood  while  it  is  being  planed.  Two  planes  are 
required  to  begin  with,  a jack  plane  and  a smooth  plane. 
A good  fine  cross-cut  saw  will  probabh^  answer  for 
all  ordinary  sawing,  and  it  may  be  used  as  a rip  saw 
when  only  a little  of  this  kind  of  work  is  required.  Two 
chisels,  one  f inch,  the  other  | inch,  and  two  gouges  of 
about  the  same  width,  will  be  needed.  A hammer  and 
a screwdriver,  together  with  a brad  awl  and  a foot  rule 
complete  an  outfit  that  will  enable  the  owner  to  do  a 
great  deal  of  work. 

Of  course  a good  oil  stone  should  be  at  hand  for 
sharpening  the  tools,  and  they  should  be  kept  sharp. 

Chisels  and  plane  irons  must  be  held  at  an  angle  of 
about  60°  to  the  surface  of  the  stone  and  moved  back 
and  forth  on  the  stone  until  an  edge  is  produced.  The 
straight  side  of  the  tool  must  be  kept  from  the  oil  stone. 

While  the  tool  is  being  sharpened  the  oil  stone  must 
be  lubricated  with  a few  drops  of  sewing  machine  oil  or 
bicycle  oil.  When  the  tools  need  grinding  it  is  advis- 
able to  have  the  work  done  by  a competent  workman. 

The  plane  irons  are  set  so  that  the  edge  is  seen  all  the 
way  across  the  wood  of  the  plane  and  secured  by  driv- 


1C 


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injj  in  the  wedge.  If  the  tool  proj(‘ets  so  as  to  make  a 
thick  shaving,  the  wedge  is  loosened  slightly  and  the 
iron  is  made  to  rise  slightly  hy  lajtjting  with  a.  hammer 
on  the  top  of  the  plane.  The  iron  may  lx*  adjusted  lat- 
erally by  tapping  the  iron  on  one  (“dge  or  the  other  near 
the  to]>,  and  it  may  he  forced  downward  by  a few  light 
taps  on  the  upper  end. 

After  some  observation — every  hoy  has  opportnniti<‘S 
for  observation — and  after  practice,  the  amateur  will 
be  able  to  do  an  ordinary  job  of  car])entry,  and  he  will 
seek  after  a few  more  tools,  such  for  example  as  a try- 
square,  a bit-stock  and  a few  hits,  a few  clamps  and  a 
glue  pot.  He  can  then  enter  into  the  work  heartily,  and 
not  only  make  needed  repairs,  hut  construct  many  plain 
little  articles  such  as  boxes  Avith  hinged  covers,  cabi- 
nets, screen  frames,  etc.  The  main  requirements  are  to 
construct  each  part  as  carefully  as  possible,  to  assem- 
ble the  parts  with  equal  care,  and  to  never  use  plugs  or 
putty,  or  in  other  Avays  patch  up  for  bad  Avorkmauship. 
If  a mistake  is  made,  it  is  generally  better  to  throAv  the 
part  aAvay  and  begin  again  rather  than  to  patch. 


WHITTLING 

The  boy  who  is  a good  Avhittler  Avill  make  a good  me- 
chanic, or  Avill  at  least  understand  mechanics  aa'cII 
(‘iioiigh  to  knoAv  a good  job  from  a poor  one,  and  Avill 
be  abl(‘  to  help  himself  in  many  an  emergency.  Heal 
[)roliciency  Avith  a jack-knife  implies  a knowledge  of 
mechanics  and  exhibits  an  ai)litude  for  meidianical 
Avork  Avhich  only  needs  op[)ortunity  and  encouragement 
lo  reach  a,  useful  stage  of  d(“V(‘lo])ment. 

A jack-knife  is  a v(‘ry  simph'  tool,  but  Avithout  doubt 


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17 


it  is  more  generally  useful  than  any  other.  For  whit- 
tling, an  ordinary  two  or  four-bladed  knife  should  be 
selected.  It  should  have  a good-sized  handle  and  its 
blades  should  be  fine  and  well  tempered.  With  the 
knife  should  be  purchased  a fine,  sharp  oil  stone,  and 
the  knife  should  be  kept  sharp,  as  it  is  impossible  even 


Fig.  14.  Knives  adapted  for  Whittling. 


for  an  expert  workman  to  do  good  work  with  a dull 
knife. 

In  sharpening  the  knife,  the  blade  should  be  kept  at 
an  angle  of  about  20°  with  the  face  of  the 
stone  and  rubbed  back  and  forth  the  full  length  of  the 
stone  about  an  equal  number  of  times  for  opposite  sides 
of  the  blade,  until  it  appears  to  be  sharp,  the  stone 
meantime  being  lubricated  with  water  or  oil ; then  it 
may  be  stropped  like  a razor  on  a strip  of  leather  until 
it  is  literally  as  sharp  as  a razor. 

In  whittling  curious  and  ornamental  objects,  sea- 
soned straight-gi’ained  white  pine  should  be  selected. 


18 


llOiMK  AIl^X’IIAXK'S  F()l{  AMATKl'IfS 


TIi(‘  piece  should  be  a little  ]ar<i;er  than  (li(‘  finished 
Avork,  and  tlu*  desiiiu  should  he  laid  out  in  jxuieil  on  one 
side  of  the  block,  Avheii  it  can  be  saAvc'd  out  with  a scroll 
saw.  If  the  form  eau  be  traced  on  tin*  edj^e  of  the  Avoi-k 
much  Avhittliiij?  may  be  avoid(‘d  by  doin<i  more  sawiu}^. 
The  knife  work  may  now  ])roee(Ml.  It  is  well  to  bejiin 
Avith  the  lieaA'ier  portions  and  finish  AA'ith  the  lighter 
])oi‘tions. 

As  much  should  be  done  as  possible  AA  ithout  tin*  use 
of  sand  paper.  If  it  can  all  be  done  AA  ithout  sand  ])a])(‘r 
so  much  the  better.  It  Avill  sometimes  be  found  nec- 
essary to  lAut  on  the  finishing  touches  Avith  a pi<*ce  of 
A'cry  flue  sand  }(ai)(*r.  Blades  of  different  forms  are 
found  useful,  and  in  some  kinds  of  Avork  a ])enknife 
blade  AA’hich  has  been  broken  off  rather  short  aa  III  proA’e 
e.xceedingly  useful  AA’hen  the  blade  has  been  repointed. 

The  saAA’  used  for  shaping  the  AA’ork  may  be  like  the 
one  on  pages  12  and  13,  or  one  of  the  small  scroll  saAA’- 
ing  machines  so  much  in  use  at  one  time  AA’ould  be  still 
better. 

A A’ery  pretty  example  of  whittling  is  the  chain  AA’hose 
liidvs  are  formed  from  a single  bar  of  Avood  of  0-shaped 
cj'oss  section.  To  make  a good  job  the  bar  should  be 
(‘venly  spaced,  and  the  links  draAvn  on  the  sides  of  the 
bar.  Th(*n  boles  are  bored  diagonally  through  the  bar. 
i\t  the  angle  the  cutting  proceeds  sloAA’ly  and  cautious- 
ly, finishing  tin*  link  as  far  as  possible  before  it  is  cut 
loose.  If  any  sandixipering  is  to  be  done  it  should  be 
done  as  far  as  }Missibl(!  before  the  link  is  cut  loose.  In 
flu*  exam])l(‘  shown,  only  a ])ortion  of  the  AA'ooden  bar 
has  been  foiMiied  AA’ilh  links,  fhe  remainder  l)eing  left 
fo  giv<‘  an  idea  of  lh(‘  melhod. 

It  is  more  dilflcult  to  A\hiflle  a pair  of  pliers  from  a 


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19 


single  piece  of  wood,  so  that  the  jaws  work  freely,  and 
at  the  same  time  the  joints  are  neat. 


Fig.  15.  Examples  of  Whittled  Work. 


The  blank  for  the  pliers  is  sawed  from  |-inch  pine. 
The  sides  of  the  pliers  where  the  joint  is  to  be  formed 
are  finished  and  the  joint  is  carefully  laid  out  in  fine 


20 


JiOJIE  MECHANICS  E<)1{  AMA'I'EniS 


lines.  Then  with  a veiy  thin  knife  Ithuh*  inserti'd  from 
eaeh  side  tlie  eentral  ])()rtion  of  the  joint  is  cnf  tlii-oii<;h  ; 
thin  incisions  are  made*  in  the  sides  to  intersect  tlie 
otlier  ents.  Tlie  jaws  of  tlie  jdiers  are  eariTiilly  seji- 
arated  by  cnttinfj  from  either  side*,  and  tli(“  cuts  which 
separate  tlie  inside  piece  arc*  then  made  with  uri'at  care. 
The  outside  of  the  jaws  and  the  handles  ar<'  now  fin- 
ished. In  cnttiiijn'  the  joint  tin*  wood  is  somewhat  com- 
pressed by  the  insertion  of  th(‘  knife*,  and  tin*  joint  aji- 
pears  badly  made.  Ily  soaking-  the  wood  in  water  for 
a lialf-honr  or  so  the  wood  ri'snmes  its  normal  condi- 
tion, and  the  joint  becomes  tiuht.  When  the  wood  is 
dry  the  finishing'  may  be  done  with  a knife  and  with 
fine  sand  paper. 

The  tower  containing  the  balls  and  the  revolving 
spindle  is  cut  from  a single  bar  of  wood,  with  the  balls 
and  spheroid  formed  with  a knife  in  the  places  they 
now  occupy.  The  design  is  carefully  drawn  on  the  bar, 
and  the  work  begins  by  making  a diagonal  cut  across 
each  corner  for  the  corner  posts,  not  cutting  through 
the  floors  of  the  different  stories.  Then  the  inner 
postern  is  cut  roughly  in  the  form  of  a cylinder.  The 
cross  cuts  are  then  made  and  the  pieces  are  shaped  into 
balls.  The  spindle  in  the  lower  story  is  formed  in  the 
same  way,  but  it  is  cut  loose  by  running  the  point  of 
the  knife  into  the  apexes  of  the  cones  formed  above 
and  below  the  sjdu'roid,  thus  at  one  ojieration  forming 
the  points  of  tin*  sjiindle  and  tin*  bearings  for  them. 
The  posts  at  tin*  coi*n(‘rs  an*  h'ft  as  large  as  possible 
and  finished  finally  by  taking  off  only  enough  wood  to 
make;  th(“m  straight  and  scpiare. 

An  anchor  with  its  cross  bar  and  ring  is  made  of  a 
single  |)i(‘c(*  of 'wood  a little  thicker  than  the  width  of 


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21 


the  flukes.  The  cross  bar  is  whittled  out  parallel  with 
the  shank  of  the  auchor,  and  the  curved  end  is  cut 
across  the  grain.  The  hole  in  the  shank  is  formed  at 
the  same  time  the  curved  end  is  cut  loose.  The  shoulder 
on  the  bar  is  thus  formed  aud  the  bar  is  pushed  through 
the  hole  in  the  shauk.  A small  mortise  is  made  in  the 
bar  to  receive  the  key  which  keeps  it  in  place.  The  ring 
at  the  top  of  the  anchor  is  made  in  the  same  manner  as 
the  first  link  of  the  chain.  The  anchor  looks  very  sim- 
ple, but  it  is  in  reality  quite  difllcult. 

In  all  these  examples  the  wood  should  not  be  cut 
away  more  than  is  necessary,  except  to  finish. 

The  puzzle  shown  assembled  and  separated  cannot 
readily  be  described.  The  pieces  are  notched  so  that 
they  will  go  together  and  form  the  symmetrical  whole, 
as  shown  in  the  engraving. 


DIFFERENT  SHAPES  OF  SAW  TEETH  AND  THE 

WAY  THEY  CUT* 

The  accompanying  sketches  show  the  different  shapes 
of  saw  teeth  and  the  way  that  they  cut  the  timber.  Fig. 
16  shows  the  dress  of  a shingle  saw  tooth.  By  examin- 

Fig.  16.  The  “ Dress  ” of  a Shingle  Saw  Tooth. 

ing  it,  it  will  be  seen  that  it  is  a “sprung  tooth,”  and 
the  teeth  cut  on  alternate  sides  of  kerf,  taking  two  teeth 
to  clear  out  the  kerf  on  both  sides.  The  bevel  of  the 
teeth  gives  it  a shear  cut  on  the  timber.  The  wood  will 
slip  on  the  edge  of  the  teeth,  Avearing  them  on  the  inside 
and  leaving  the  outer  corner  full  aud  sharp,  and  a cor- 
* PYom  the  Saw  Mill  Gazette. 


22 


IIOMH  MF.(MIANirS  FOI?  A^F\TFr^?S 


iK^r  to  (‘lear  np  ili(^  si(l(‘  of  tlu‘  k(M'f,  (Inis  inakinu^  sinoolli 
lumber. 

V\<^.  17  shows  a sipiare  dresscnl  tootli.  Tlie  wood 


Fig.  17.  A Square 
Dressed  Tooth. 


Fig.  18. 

A Vertical  Saw  with  Square  Teeth. 


wears  off  tlie  corners,  leaviiii>  tliem  dull,  and  they  will 
tly  from  timber  to  the  other  side  if  the  wood  is  not 
(M]ual  in  hardness,  and  lead  the  saw  to  that  side  of  tlie 
log.  This  trouble  is  found  in  wood  with  a hard  and 
soft  grain  or  in  knots,  hut  with  the  beveled  teeth  the 
sharp  corner  will  lead  the  saw  straight. 

Fig.  18  shows  a vertical  saw  with  square  teeth,  a very 
(‘ommon  dri^ss.  The  wood  wears  the  out  corner  off, 
leaving  it  round  or  blunt,  and  as  there  is  nothing  to  sup- 
port the  inside  of  the  teeth,  they  will  fly  from  the  wood, 


Fig.  19.  A Swaged  Tooth  of  the  Same  Kind  as  Fig.  18. 


I In*  kiM-f  iinlil  worn  in  lli(‘  slia|)(*  shown  in  (ait. 

Fig.  1 !)  is  a swag(*d  tool  b of  I li(‘  sanu^  kind  of  saw  and 
is  a v(*ry  good  dress  for  sash,  miil(\y,  gang,  and  other 


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23 


saws  using  light  feed,  but  for  heavy  feed  it  is  better  to 
swage  the  teeth  out  on  both  sides  and  joint  off  for  set. 
By  referring  to  Fig.  20  it  is  seen  that  all  teeth  of  this 
shape  cut  with  a scrape  cut,  not  with  edge  cutting,  like 


Fig.  20.  Teeth  that  Cut  with  a Scrape. 


a chisel,  but  with  the  edge  set  at  right  angle  with  the 
line  of  cut.  For  soft  wood,  such  as  white  pine,  ham- 
mer the  top  of  the  teeth,  turning  the  edge  down  enough 
to  give  a cutting  edge  dotvnward.  Figs.  21  and  22  are 
circular  log  saws. 

Fig.  21  shows  a side  view  of  a tooth.  It  is  seen  that 
the  back  of  the  tooth  lies  close  to  the  wood,  and  the 


Fig.  21.  Side  View  of  Circular  Saw  Tooth. 

tooth  may  be  tiled  thin  without  danger  of  breaking. 
This  dress  of  saws  cut  with  a chisel  cut,  will  carry  more 
feed  than  any  other,  and  at  the  same  time  do  the  best  of 
work. 


^4 


MKCTIANICS  FOU  AMATEURS 


Fic;.  22  shows  tlio  shape  of  tlie  edge  of  the  same  tooth.. 
It  heiiijn  hollow  on  the  (“dji’e,  with  the  coiaiers  shar]), 
the  wood  will  tly  or  slij)  from  the  eoniei's,  not  weariiiij; 
them  as  much  as  a S(inare  tooth,  leaving  a i^ood  corner 


Fig.  22.  Fig.  23. 

Edge  of  Circular  Saw  Tooth.  A Square  Dressed  Tooth. 

to  clear  the  sides  of  the  kerf.  It  will  be  seen  by  refer- 
rintf  to  Fig.  22  that  it  takes  two  teeth,  one  on  each 
side  of  the  saw,  to  cut  both  sides  of  kerf,  bat  in  this 
dress  each  tooth  cuts  both  sides,  and  again,  if  a beveled 
sjirnng  tooth  is  forced  to  do  more  than  a medium 
amount  of  duty,  it  will  fly  into  the  wood  and  be  in  dan- 
ger of  tearing  off  the  teeth. 

In  Fig.  23  is  si'cn  a square  dressed  tooth.  All  teeth 
swaged  with  a sipiare  dress  leave'  the  corners  rather 
weak  and  not  much  to  joint  off  the  side  in  setting, 
n'his  shows  om*  snch  tooth  cutting  throngh  cross 
grained  or  twisled  timbi'r,  a sharp  corner  but  nothing 
1o  ch'ar  the  side  of  tlii*  keiT,  the  cross  grain  filling  so 
rnncli  of  Ihe  kerf  as  to  rub  on  the  plate  of  the  saw  and 
heat  it. 


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as 


Fig.  24  refers  to  a dress  for  hand  and  other  saws  that 

Pig.  24.  Dress  for  Hand  and  other  Saws. 

is  used  for  cross-cutting  soft  wood  that  is  to  be  cut  very 
smooth. 


A WEINKLE  IN  SAWING 

A trj-square  is  not  ahvays  at  hand  when  it  is  desired 
to  saw  a stick,  and  Avlien  it  is  handy  some  mechanics 
prefer  to  work  “guess”  than  otherwise.  When  a 
bright  straight  saw  is  placed  upon  a stick  or  on  the  edge 


Pig.  25.  Reflection  Substituted  for  the  Try  Square. 

of  a board,  the  reflection  of  the  stick  or  board  in  the 
saw  is  sufticieutly  well  defliied  to  permit  of  placing  the 
saw  so  that  the  reflected  image  coincides  with  the  object 
reflected,  forming  a continuous  straight  line.  If  the 
sawing  is  done  while  the  image  and  the  stick  are  in  line, 
tlie  stick  will  be  cut  at  right  angles. 

It  is  obvious  that  a line  may  be  drawn  at  right  angles 
to  the  stick  by  arranging  the  saw  as  shown  in  Fig.  26. 
If,  after  forming  this  line,  the  saw  be  placed  across  the 
stick  so  that  the  line  and  its  reflected  image  and  the 


HOME  MECHANICS  FOE  Ai\IATEUJ^S 


26 

sti(*k  and  its  r(di(M‘t(‘(l  iinaji^e  form  a scpiaro,  witli  tla^ 
reflected  ima<>e  and  the  stick  lying  in  tlie  same  plane, 


Fig.  26.  Laying  out  Work  by  Reflection. 


Fig.  27.  Forty-five  Degree  Angle  by  Reflection. 

as  shown  in  l^hg.  27,  the  stick  may  be  sawed  at  an  angle 
of  fo]*ty-tiv(^  d(^grees,  provided  the  saw  is  held  in  the 
saim^  ])osition  ridative  to  the  sti(‘k. 


WOOD  CAKVING 

To  one*  having  an  id(‘a  of  foian  and  pro])ortion,  wood 
carving  is  not  venw  diflicailt,  (‘ven  though  a practical 
kno\\’h‘dg(‘  of  drawing  and  imxhding  he  wanting.  Cred- 


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27 


itable  specimens  of  carving  liave  been  produced  by 
means  of  the  pocket  knife  alone,  by  persons  having 
dextrous  bands  and  good  e^^es;  but  it  takes  a good 
workman  to  produce  a fine  job  with  poor  tools,  or  none 
at  all,  therefore  the  average  wood  carver  will  be  obliged 
to  rely  somewhat  upon  tools  and  appliances.  In  fact, 
the  more  complete  the  set  of  tools  and  the  more  perfect 
the  accessories,  the  more  readily  can  the  work  be  done 
and  the  more  satisfactorv  the  I’esult. 


Fig.  28.  Violet  Panel. 


The  principal  tools  are  gouges,  chisels,  parting  tools, 
curved  and  straight,  a heavy  mallet,  a light  mallet,  a 
solid  bench,  and  some  clamps.  As  to  materials:  For 
the  beginner  soft  woods  are  best,  such  as  pine,  white 
wood,  or  cedar.  After  a little  experience,  pear,  black 
walnut,  and  oak  may  be  tried.  Nine-tenths  of  the  dif- 
ficulty in  carving  is  in  working  one’s  self  tip  to  the 


28 


IJOMI-:  MI'XUIANK’S  KOK  AMA'I'Kin.’:^ 


point  of  settiii”'  out  in  (In*  work.  Tin*  clianccs  nro  lluit 
in  tlio  bc^innini'  tin*  tyro  will  not  succeed  in  ])ro(lncin^ 
the  exact  forms  desired  ; but  ])rof>ress  will  be  mad(“  with 
every  successive  trial. 

It  is,  indeed,  diltieult  to  give  any  <“X])lieit  diiaa-tions 
for  carving.  W(‘  niigbt  almost  say,  bere  are  tin*  ma- 
terials, tbe  tools,  and  tbe  design.  The  wliob*  of  carving 
is  to  take  these  tools  and  cut  this  d(‘sign  from  this  ])i(‘C(^ 
of  material,  using  your  own  judgment,  at  the  same 
time  “making  haste  slowly.” 


Fig.  30. 

Fig.  29.  Carving  Tools.  Edge  View 

of  Tools. 


'I'he  (ools  re(|uired  ai’C  shown  in  Fig.  29,  1 being  a 
firmer,  2 a straight  gouge*,  2 a curved  gouge,  4 a bent 
chisel,  o a fronl-beni  gemge,  (»  a back-bent  gouge,  7 a 
parliiig  lool,  <S  a curved  parling  lool,  and  9 a macaroni 
fool.  1'hes(‘  fools  can  be*  pui‘e‘hase*d  e*ithe*r  se*])arate*ly 
eir  ill  se*ls.  4'he‘re*  are*  e)fhe*r  forms  ami  many  elilfe*r(*nt 


HOME  MECHANICS  EOR  AMATEURS 


29 


sizes.  It  is  well  to  begin  with  a half  dozen  medinin 
sized  tools,  and  then  learn  by  experience  what  further 
tools  are  required.  A flat  and  curved  chisel  and  a flat 
and  curved  gouge,  each  one-half  inch  wide,  a narrow 
deep  gouge,  and  a parting  tool  are  sufficient  for  the 
first  effort. 

The  design  is  marked  upon  the  wood  to  be  carved, 
and  the  outline  is  shaped  by  means  of  a scroll  saw,  if 
the  design  is  to  be  in  high  relief,  and  the  most  promi- 
nent is  isolated  from  the  rest.  Avoid  cutting  too 
deeply,  or  raising  slivers  that  run  into  the  wood  and 
spoil  the  work.  Where  the  carving  is  done  on  a flat 
surface  in  low  relief,  gouges  having  little  curvature 
are  required. 

The  tools  shoxdd  be  kept  as  sharp  as  possible,  to  se- 
cure smooth  Avork  and  to  economize  labor.  Carving 
tools  are  usually  sharpened  from  both  sides  by  means 
of  suitable  oil  stone  slips  and  by  leather  strops  charged 
Avith  crocus. 

The  Avood  Avhile  being  carved  is  held  in  place  on  the 
bench  by  means  of  screAv  clamps,  or  by  pointed  screAvs' 
passing  upAAard  through  the  bench  into  the  back  of 
the  Avork. 

In  Fig.  28  is  shoAvn  a panel  of  violets,  Avhich  may  be 
copied  after  some  experience  is  gained.  It  is  easier, 
hoAveA^er,  to  copy  other  carvings  than  to  produce  the 
Avork  from  engravings. 

Simple  subjects  should  be  chosen,  and  no  Avork 
should  be  passed  until  it  has  been  made  as  perfect  as 
the  tools,  materials,  and  ability  of  the  carver  Avill  per- 
mit. A final  finish  imparted  Avith  fine  sandpaper  is  ad- 
missible ; but  neither  sandpaper  nor  putty  should  be  de- 
pended upon  as  material  aids  in  this  kind  of  work. 


PART  II. 


HOW  TO  MAKE  HOUSEHOLD 
ORKAMEKTS 

HOME  MADE  GRILLES  AND  GRATINGS 

A DWELLING  HOUSE  without  ornamentation 
of  the  class  mentioned  above  indicates  one  of 
three  things — either  the  owner  or  occupant 
does  not  appreciate  the  value  of  this  kind  of 
home  decoration  or  he  does  not  possess  the  skill  to 
make  or  the  power  to  purchase  it.  It  is  true,  the 
beautiful  metal  and  wood  work  now  manufactured  for 
this  purpose  is  very  expensive ; but  it  is  also  true  that 
something  equally  as  beautiful  may  be  had  without 
much  trouble  or  expense. 

The  grilles  shown  in  Figs.  31,  32,  and  33  are  made  of 
rope,  sized,  bent  into  shape,  dried,  glued  in  a wooden 
frame  and  finally  painted  an  appropriate  color  or 
gilded  or  bronzed.  These  ornaments  when  placed  in  a 
doorway  or  window  or  across  a hall  from  the  stairway 
to  the  wall,  or  in  some  corner  in  the  library,  add  won- 
derfully to  the  appearance  of  the  room. 

The  materials  required  are  some  A inch  sash  cord, 
glue,  round  sticks  or  doweling  A inch  in  diameter, 
paraffine  (a  paraffine  candle  will  do),  some  strips  of 
wood,  and  paint  or  varnish. 

There  are  in  the  present  case  only  two  fundamental 
forms  for  the  spindles  or  bars,  but  these  are  combined 
in  several  different  ways,  as  shown  in  Fig  36.  The  spin- 

[31J 


32 


HOME  MECHANICS  FOR  AIViATEURS 


die  most  used  is  shown  in  Fi<r.  34.  It  is  formed  by 
windinc:  tlie  sasli  cord — wliich  lias  lieen  jirevionsly 
stee])ed  in  the  "lue  size — ujion  the  wooden  rod.  The 
rod  is  coated  with  melted  ])aral1ine  before  use,  to  ]»re- 
vent  the  size  from  adhei-inin’,  and  e(|uidistant  marks  ar(> 
made  upon  the  rod  as  unides  for  the  windinii.  These 
marks  are  H inches  a])art.  The  windiiii^  can  be  easily 
done  by  jilaciii”'  one  (md  of  tin*  woodim  rod  in  a vise, 
drivino-  a tach  through  the  end  of  the  I'ojie  into  the  rod. 
If  every  turn  of  the  rojK*  ai'onnd  the  7‘od  is  made  to  co- 
incide with  one  of  the  marks,  tin*  s])indle  will  be  true 
enoipcih  for  all  purposes.  A tack  should  be  driven 


Fig.  31.  Grille  for  Double  Doors. 


through  the  end  of  the  finished  spiral  into  the  rod  to 
prevent  the  rope  from  unwinding.  A number  of  rods 
will  be  reciuired.  Part  of  the  spindles  should  be  wound 
in  a rigbt-banded  direction  and  tbe  remainder  in  a 
left-hamb'd  direction.  The  rope  should  be  allowed 
to  stand  for  a day  or  so  to  dry.  It  is  well,  espe- 
cially in  warm  weathei',  to  add  to  the  size  some  oil  of 
cloves  or  (airbolic  acid  to  prevent  it  from  souring  while 
drying. 

Tin-  othei'  form  of  spindle  is  shown  in  Fig.  35.  This 
is  made  by  bending  the  siz(>d  rope*  around  pins  driven 
into  a board  in  two  rows,  tin*  pins  of  one  row  alternat- 


HOME  MECHANICS  FOR  AMATEURS 


33 


Fig.  32.  Rope  Grille  for  Window,  Door,  or  Hall. 


ing  in  position  with  those  of  the  other  row.  The  board 
and  pins  are  covered  with  paraffine,  as  in  the  other  case. 

The  spiral  spindles  may  be  combined  with  each 
other,  as  shown  at  a,  b,  c,  d,  and  e in  Fig.  36,  and  with 


Fig.  33.  Grille  for  Window. 


31  IlOJll]  JMKCIIANJCS  FOR  AMATEURS 


a straiglit  rod,  as  sliowii  at  /.  At  fi  tliey  are  sliowii  in 
eoinbiiiatioii  with  the  zigzag  r()])(\  At  li  the  zigzag  ro])e 
is  shown  in  coinhination  witli  straiglit  rods. 

Tlie  circles  and  s(\gnients  of  ('ir(‘l(^s  sliown  in  hdgs.  ?>2 
and  33  are  made  l)y  winding  tlu^  siz(Ml  ro])e  ai'onnd  a tin 
pail,  a can,  or  some  otlu^r  (‘vlindrical  body  and  allowing 
it  to  dry.  To  form  a complete'  ring,  one  turn  of  the  i'0])e 
is  cut  off,  its  (‘lids  are  cut  off  diagonally  and  fastened 
together  with  strong  glue. 

The  spindles  arc'  cut  by  means  of  a sharp  knife.  The 
various  parts  of  tlie  work  are  fastem'd  togetlu'r  and  at- 
tached to  a light  wooden  frame,  and,  as  a rule',  no  fas- 
tening other  than  glue  Avill  lie  reepiirc'd.  If,  liowevc'r,  a 
stronger  fastening  is  nec'cssary  at  some  jioints,  small 
brads  or  wire  nails,  or  even  screws,  may  be  used. 

In  Fig.  33,  the  rosette,  is  formed  of  a circular  ring 
filled  with  segments  of  a similar  ring  in  the  manner 
shown.  Each  pair  of  spirals,  consists  of  one  right- 


Fia.  34.  Spiral  Spindle. 


handeil  oik*  and  om*  l(*ft-hand(*d.  The  spindles,  h, 
a F*('  spii'als. 


HOME  MECHANIC'S  FOR  AMATEURS 


35 


manner  as  wood.  They  may  be  stained  or  painted  to 
match  the  work  into  wliich  they  are  fitted,  or  they  may 
be  painted  white  and  relieved  by  a little  gilt  on  the  pro- 
jecting part. 

It  is  obvious  that  a large  number  of  patterns  may  be 
worked  out  by  the  aid  of  these  suggestions.  Different 


Fig.  36.  Forms  of  Spindles  and  Bars. 


kinds  and  sizes  of  rope  may  be  used  alone  or  in  combi- 
nation. 

These  grilles  may  be  placed  in  windows,  doorways, 
across  halls,  above  mantels,  across  niches,  between  win- 
dows, and  in  many  other  places  which  will  suggest 
themselves.  Like  many  other  household  ornaments,  if 
well  and  carefully  made,  they  will  repay  the  labor  and 
trouble  of  making. 

WALL  ORNAMENTS 

There  is  a great  deal  of  satisfaction  in  the  possession 
of  home  made  ornamental  objects,  because  they  are  the 
work  of  one’s  own  hand,  and,  besides  this,  they  are  not 
obtained  by  the  expenditure  of  money  that  might  per- 
haps, be  needed  for  other  purposes. 

Ornaments  belonging  to  the  wall  go  a long  way  in 
furnishing  and  beautifying  the  house.  Pictures,  care- 


IIOJIM  MI-X'IIAN’ICS  Foi;  .\:\r.\'l'KU KS 


XG 

fully  sel(*(‘t('(l,  arc*  liijilily  <“(r(“c( iv(“.  Many  of  (la*  nio<l- 
(“I'li  |)liot<)i>ra])lis,  ]>liol()-,i>vavur(‘s,  and  jilioto-ciijui'aviiiii's 
which  are  rc'ally  iiK'riloiMous  can  l)e  ohiaiued  for  lifiy 
(■(‘iits  or  a dollar  (“acli.  Soin<“  fairly  nood  elchiii^s  and 
imitations  of  water  colors  ai-e  also  sold  at  reasonahh^ 
])rlces.  Th(‘  jii'cat  il<*ni  in  conn<“clion  wilh  a low-]>riced 
l)ictnre  is  the  fi-ann*;  hnt  any  one  with  such  tools  as  are 
commoidy  found  about  tin'  house*  and  with  a small 
(inantity  of  mat<*rial  can  readily  make  a Aai'iety  of 
frames  Avorthy  (»f  any  ])lace  in  the  house*. 

The  sim])l(*st  frame?  tee  make*  is  that  sheeAvn  in  Fi_y  .‘>7. 
This  is  maele*  freem  a narreew  tiat  beearel  eef  e*he*stnnt, 


Fig.  37.  Wooden  Frame. 


l)uli(‘i*Tni1,  ()]*  (‘V(Mi  asli  or  oak,  liavini»“  its  inner  ed<»‘e 
i'al)l)(*1(*(l  io  r(MM‘iv(‘  ili(‘  i^lass,  mat,  and  l)a('kin<»‘.  Tliis 
sli'ip  is  stained  and  (inisln*'!  b(‘ror(‘  ii  is  mit(a'(Ml.  Tlie 
staining  is  doin*  by  brnsbin<»-  lli(‘  strip  (‘V(ady  witli  a 
thin  coating-  of  asi)lial tnin,  or  with  a thin  slain  of  log- 


HOME  MECHANICS  FOR  AMATEURS 


Z1 


■wood,  or  Avith  a stain  forniod  of  either  of  the  following 
dry  pigments,  burnt  umber,  burnt  or  raw  sienna,  mixed 
with  turpentine  and  a very  small  proportion  of  boiled 
linseed  oil.  Chemical  ink  or  writing  fluid,  reduced 
with  water  so  as  to  produce  a greenish  gray  tint, 
answers  a good  purpose. 

After  the  stain  is  dry,  the  tint  is  lightened  along  the 
inner  or  outer  edge  of  the  strip,  as  taste  may  dictate, 
by  scraping  the  wood  by  means  of  an  ordinary  wood 
scraper,  or  by  rul)l)ing  the  surface  down  by  means  of 
fine  sandpaper.  It  is  obvious  that  the  stain  may  be 
applied  to  the  wood  in  such  a way  as  to  graduate  the 
tint  without  the  necessity  of  scraping  or  sandpapering, 
but  this  requires  practice. 

The  tint  should  be  so  graduated  as  to  be  very  light, 
or  nearly  the  natural  color  of  the  wood  at  one  edge  of 
the  strip,  while  the  other  edge  should  be  quite  dark. 
The  strip  may  be  finished  by  flowing  over  it  three  thin 
coats  of  shellac  varnish,  allowing  each  coat  to  dry  thor- 
oughly before  axqilying  the  next.  The  first  two  coats 
should  be  rubbed  down  with  very  flue  emery  paj^er 
after  they  become  thoroughly  dry  and  hard.  The  last 
coat  may  be  left  bright,  or  its  luster  may  be  toned 
down  by  means  of  the  fine  emery  pax>er.  The  mould- 
ing or  strip  thus  xjrejjared  is  mitered  in  the  usual  way 
by  the  aid  of  a miter  box,  and  nailed  and  glued  to- 
gether at  the  corners. 

The  mat  in  this  case  consists  of  a piece  of  thick  paste- 
board in  which  is  cut  an  opening  of  the  desired  form. 
The  edges  of  the  pasteboard  are  beveled  around  the 
opening,  and  canvas,  crash  toweling,  or  white  or  tinted 
cotton  velvet  is  secured  to  the  pasteboard  by  means 
of  bookbinder's  paste  (flour  paste  with  glue  added). 


38 


HOME  MEC'JIANK'S  FOR  AJIATEUIJS 


After  tlie  paste  becomes  dry,  if  desii-ed,  a design  may 
be  painted  on  tlie  mat  witli  wat(‘r  colors. 

The  frame  sliown  in  Fijjc.  38  is  made  on  a different 
plan.  In  this  case  the  wooden  monldinij  is  half  round 
on  its  face.  A saw  kerf  is  made  at  the  inmm  side  of  tin* 
rabbet.  The  edji’e  of  a strip  of  white  or  “ivoiw”  zylon- 
ite  is  inserted,  in  the  saw  kerf,  and  held  there  by  a thin 


Fig.  38.  Zylonite  Frame. 


strip  of  Avood  glued  in.  A small  percentage  of  glycer- 
ine or  even  common  molasses  should  be  added  to  the 
glue  used  for  this  pur])ose.  The  zylonite  is  AAu^apped 
around  the  moulding  and  fastened  by  means  of  a thin 
strip  of  wood  laid  ov(U'  it  and  secured  by  small  nails  or 
brads.  cormu'S  of  ibis  frame  are  formed  by  means 

of  r(M‘tangular  blocks  of  Avood  paint(Hl  Avhite  on  their 
si(l(is  and  furnish(‘d  on  tlu^  front  with  a scpiare  of  zylon- 
it(^  li(*ld  in  pla(‘(‘  l)y  an  ornaimaital  bi'ass  nail. 

if  a larg(*i*  fraim^  is  i‘(‘([uir(‘d,  that  (‘an  b(^  made  Avith 


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39 


a single  strip  of  zylonite,  the  joint  may  be  covered  by 
means  of  a curved  half  round  strip  of  brass  well  pol- 
ished and  lacquered,  and  applied  as  shown  in  the  en- 
graving. 

This  frame  may  have  a gilt  lining  as  well  as  the  mat. 
It  has  a verj^  chaste  appearance,  looking  much  like  a 
frame  of  ivory,  and  it  is  withal  durable. 


Fig.  39.  Feather  Ornament. 


A very  pretty  and  easily  made  wall  ornament  is 
shown  in  Fig.  39.  It  consists  of  a number  of  peacock 
feathers  arranged  I’adially  or  in  the  form  of  a fan  witli 
the  quills  attached  to  an  elliiitical  piece  of  pasteboard 
by  means  of  sealing  wax.  The  pasteboard  is  fitted  to 
an  iridescent  shell  and  fastened  in  with  sealing  wax. 
A wire  loop  inserted  in  the  pasteboard  serves  for  hang- 
ing the  ornament.  It  may  be  placed  between  windows, 


40 


nOMH  MKdIIANICS  F()|,>  Ai\[.\TETIKS 


!il)(>vo  or  bolow  ])ictiir(‘s,  juid  in  iiuuiy  olli(‘i‘  ]>lac(‘s  wifli 
fiood  effort. 

Iti  Fi.i'-.  40  is  sliowii  a wall  cabiiuff,  wliicli  is  not  only 
liiyldy  ornamental,  but  V(‘i-y  ns(‘fnl.  Tin'  body  of  (li(‘ 
oabinet  is  of  pirn*  (tr  otber  soft  wood.  Tin*  doors  ai-e 


Fig.  40.  A Wall  Cabinet. 


io  r(‘(‘(MV(^  tlie  Ix^autifiil  zyloiiite  bas-reliefs 
sold  by  lli(‘  inaniifacd iir(‘rs  of  this  sii])erl)  material.  In 
opcMiiii^s  in  11i(‘  l)aek  of  ilu^  (‘abim^t  are  inserted  oriia- 
nnads  of  lln^  sann*  (diai'acter.  They  rescmible  ivory 
and  ar(*  v(a'y  s(‘r\ie(*abl(\ 

Th(‘  body  of  IIk^  eabin(‘t  is  m^atly  eovcaxHl  witli  (*an- 


HOME  MECHANICS  FOE  AMATEUES 


41 


vas,  toweling,  or  lighth^  tinted  cotton  velvet,  on  Avhicli 
are  painted  designs  in  water  or  oil  colors.  The  edges 
of  the  shelves  are  preferably  covered  with  sheet  zylon- 
ite,  although  they  may  with  good  effect  be  covered  with 
the  material  used  on  the  other  jjarts  of  the  cabinet.  Or- 
namental brass  hinges  and  trimmings  should  be  applied 
to  the  doors,  as  shown  in  the  engraving. 


PSEUDO-CEKAMICS 

The  ceramic  art  is  generally  practiced  under  condi- 
tions which  render  it  exceedingly  difficult  for  an  ama- 


Fig.  41.  Square  Vase. 


teur  to  make  progress  in  it,  even  so  far  as  to  produce 
work  of  the  most  modest  and  unassuming  character. 


4-2 


II()MI<:  MECIIANJCS  KOR  AMATEURS 


111  the  first  placi'  it  is  (lifiiciilt  to  obtain  the  jirojicr 
<]iiality  of  elay,  iinli'ss  oii<>  is  in  lln*  vicinity  of  a jiotti'rv 
or  elay  bed;  in  the  second  jilace,  even  1hon,i>h  one*  lias 
the  shill  and  practice  which  will  enahh*  him  to  shajic* 
the  clay  into  the  desired  forms,  still  it  is  dilficiilt,  if  not 
impossible  to  hake  the  work  after  it  is  done  in  othm* 
respects,  and  it  can  scarcidy  h<>  (‘xpc'cled  that  a ])ott<‘r 
will  bake  these  odd  articles.  These*  and  other  ditficnl- 


Fig.  42.  Triangular  Vase. 


<i(^s  prevent  tlie  wonld-be  aiuatenr  potter  from  attempt- 
ing wlial,  nn(l(‘r  more  favorable  eiriaimstaiu'es,  niii»lit 
lx*  f)ro(lnet i v(^  of  w'oi'ks  creditable  to  both  the  art  and 
th(^  artisan. 

K(*c(*ntly  sonui  (‘xc(‘(*dini>l y plain  aitich'S  of  i)ottery, 
with  (*xt,r(‘m('ly  siniph^  ornaimmta t ioip  (‘onsisting 
m('r(*ly  of  a lilll(‘  i)aint  and  a little^  e,Iaz(‘,  hav(‘  bec^ome 
V(a‘y  fashionabl(‘,  and  liav(‘  Ixuai  aexx^pted  as  works  of 


HOME  MECHANICS  EOE  AMATEEKS 


43 


art.  Some  of  these  articles  are  handsome,  others  are 
not.  Inasmuch  as  these  articles  have  no  practical 
utility,  they  do  not  require  to  be  made  of  materials 
either  fireproof  or  waterproof.  The  requisites  are 
simply  shape,  strength,  and  a.  resemblance  to  pottery. 

The  materials  required  for  making  imitation  pottery 
are  junk-board — a strong,  thick  board  having  a smooth 
surface — glue,  and  small  wire  nails.  The  ornamenta- 
tion may  consist  of  siich  floral  or  landscape  decorations 
as  the  maker  is  able  to  produce  if  he  or  she  be  artist 


Pig.  43.  Cylindrical  Vase. 


enough  to  paint  in  oil  colors.  Withoiit  this  ability  the 
aid  of  chronios  must  be  invoked.  This  will  certainly 
afford  very  satisfactory  results,  and  the  expense  will  be 
slight,  as  very  passable  German  chromos  may  be  ob- 
tained for  twenty-five  cents  each.  The  engravings  show 
several  examples  of  pseudo-ceramics  which  are  de- 
signed with  reference  to  the  material  to  be  employed, 
and  compare  favorably  with  the  high-priced  articles  to 
be  found  in  the  shops. 


44 


MI^XMIANI(!S  YOU  A^WTV.VU^^ 


Tli(‘  l)()(ly  of  ili(‘  vas(‘  sliowii  in  41  consisls  of 

r(H*taiiii>ulai'  ])i(M‘(‘S  of  juiik-boai'd  iiail(‘(l  and  :nln(*(l  to- 
^(Xlier  at  tlie  (‘onun's,  aft(‘r  tli(‘  fasliion  of  an  oi'dinary 
Avoodoii  box.  The  nails  used  are  tlie  small  \vii'(‘  nails 
used  in  braeket-Avork.  T1i(\a"  are  about  I br(M‘-(‘i,i>btbs 
of  an  inch  loni>’,  and  about  the  size  of  an  oi'dinary  pin. 


1 n tli(^  abs(m(‘e  of  such  nails  coiumon  pins  may  be  cut  off 
and  ns(*d  to  f>()od  advantaj>e.  Holes  for  these  nails 
nnisl  b(‘  niad(^  with  a fine-])ointed  awl.  The  bottom  of 
tli(^  vas(*  consists  of  a single  ])ie('e  of  junk-board,  Avith 
\"-sliai)(Ml  nolcli(*s  (uit  from  the  corners  to  j^ive  it  the 
b(*v  (d. 

Tli(‘  con(*av('  sid(^s  of  ilui  top  (‘onsist  of  send  ions  of 


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45 


paper  tube  such  as  is  employed  for  mailing  pictures. 
The  bead  around  the  top  is  of  wood.  Any  imperfec- 
tions in  the  joints  may  be  filled  with  a mixture  of  glue 
size  and  whiting  formed  into  a putty. 

Fig.  42  shows  a vase  which  can  readily  be  made  after 
the  above  hints.  It  is  triangular  in  form,  and  has  three 
wooden  balls  for  legs.  The  band  around  the  top  is 
merely  a narrow  strip  of  pasteboard  glued  on. 

Fig.  43  shows  a cylindrical  Aaise  made  of  a strip  of 
junk-board  scarfed  or  beA  eled  on  the  edges  and  lapped 


Fig.  45.  Elliptical  Vase. 


and  glued.  To  facilitate  bending  the  junk-board,  the 
side  which  is  to  be  outermost  in  the  vase  is  wet.  The 
bottom  is  glued  and  nailed  in,  and  the  corners  are 
rounded  with  a moderately  coai’se  file  and  sandpaper. 
A band  of  pasteboard  finishes  the  top,  and  three  or  four 
wooden  balls  form  the  legs.  The  inner  corner  of  this 
vase  at  the  bottom  may  be  filled  in  slightly  Avith  glue 
and  AA'hiting  to  strengthen  it. 


46 


HOME  MECIIANMCS  FOR  AMA4M^]UI?S 


Tlie  yn^Q  sliowii  in  Fij».  44  is  made  in  tln^  sann^  way 
as  that  last  des(‘ribed.  Tlie  bottom  is  ])lac(‘(l  al)ov(‘  tlu^ 
lattice  work.  The  latter  is  fornuMl  by  cnttini;  out  |h(‘ 
holes  with  a chisel.  The  rini»*  and  its  fixture  ai‘(‘  mad(^ 
of  wood. 

Figs.  45,  46,  and  47  are  examples  of  ^^pilgrim”  rases 
of  different  shapes.  That  shown  in  Fig.  47  is  circnlar, 
and  has  convex  sides  or  heads.  Tlie  hoo])  is  Ixmt  in  tln^ 
manner  already  described,  i.  c.,  after  first  wetting  the 


Fig.  46.  “ Pilgrim  ” Vase. 


outer  side.  The  heads  are  made  convex  by  wetting  the 
jnnkdioard  and  liammering  it  in  the  middle,  in  the  same 
way  tliat  a shoemaker  hammers  a shoe  sole,  or  tap,  to 
make  it  conv(*x,  that  is,  it  is  placed  upon  an  ordinary 
flat-iron  or  sad-iron,  and  hammered  with  a round-faced 
hamiiKa*  until  it  ac'cpiires  the  desired  convexity.  The 
sidles  ar(^  nailed  and  gliuMl  to  the  hoop,  and  a thin  paste- 
board circle  is  gln(‘d  lo  each  of  the  ('onvex  surfaces  of 
the  vase  to  form  a border.  Idle  mouth  of  the  vase  is 


HOME  MECHANICS  FOE  AMATEUKS 


47 


made  of  four  pieces  of  junk-board,  glued  and  nailed  to- 
gether and  secured  to  the  vase  by  glue.  The  legs  of  this 
vase  consist  of  two  pieces  of  paper  tube  closed  at  the 
ends  with  turned  pieces  of  wood.  The  corners  of  the 
vase  may  be  filed  and  sandpapered  to  make  it  ready  for 
further  operations. 

After  what  has  already  been  said  the  construction  of 
the  vases  shown  in  Figs.  45  and  40  will  need  no  descrip- 


tion, except  that  the  vase  shown  in  Fig.  46  has  wooden 
legs  and  wooden  strips  at  the  sides  of  the  mouth. 

The  body  of  the  vase  shown  in  Fig.  48  can  be  con- 
structed without  special  description.  The  ornamenta- 
tion consists  of  ordinary  artificial  flowers  and  vines,  se- 
cured to  the  body  of  the  vase  with  common  glue.  They 
are  stiffened  by  spraying  or  spattering  shellac  var- 
nish on  them  from  an  old  tooth  or  nail  brush.  They 


48 


nOMK  MECHANICS  V()\l  A.MATKUl^S 


{^lioiild  be  S])raye(l  tilings  io  oiye  IIkmii  a uood 

heavy  (‘oatiiii!,’  of  vaniisli.  WIkmi  tliis  l)(‘(‘oin(*s  di'y  tie* 
leaves  and  dowers  may  l)e  paintcHl  in  tln^  saim*  manii(*i* 
as  the  otlier  j)arts  of  tli(‘  vas(‘.  Tli(*se  vas(‘s  slioidd  1)(‘ 
smootldy  finished  and  tlioroni>ldy  dried  b(*for(‘  any  at- 
tempt at  finishini>‘  is  made.  Tlie  lirst  opcn-ation  in  11i(‘ 
way  of  finisldnj»-  is  to  give  the  vase  two  ('oats  of  sln^llac* 

varnish  inside  and  out, 


allowing  one  coat  to  be- 


come dry  before  the 
other  is  a])])lied.  When 
both  coats  of  varnish  are 
dry  and  hard,  which  will 
reqnire  about  two  daj'S, 
the  painting  miij  be 
done. 

It  is  not  the  design  of 
this  section  to  enter  into 
all  of  the  details  of 
painting  necessary  to 
enable  the  tyro  to  paint 
landscapes  or  flowers, 
blit  a suggestion  or  two 
in  regard  to  the  paint- 
ing will  not  be  out  of 
place.  The  best  results 
will  be  obtained  by  giv- 
ing <h(^  vas(^  two  (‘oats  of  white  paint  before  attempting 
to  lay  on  tlu^  color.  The  sides  and  bordcu'  of  the  vase 
should  be  of  a lUMdi'al  tint,  slightly  mottled.  An  olive 
green  or  a gray  looks  w(‘ll  and  gives  relief  to  any  de- 
sign lhat  may  be  chosen. 

No  attempt  should  b(^  made  to  ay)ply  the  colors 


Fig.  48.  Vase  with  Leaves 
and  Flowers  in  Relief. 


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49 


smootlily.  The  Avliole  slioultl  be  done  in  a bold,  dashing 
wav. 

If  painting  is  ont  of  the  question,  some  of  the  ehro- 
inos  before  mentioned  may  be  used  with  good  effect. 
The  edges  of  the  chromos  may  be  concealed  beneath  the 
jmsteboard  border.  In  eitlier  case  after  the  paint  on 
the  article  has  become  thoroughly  dry  and  hard,  which 
will  probably  .require  four  or  six  weeks,  it  may  receive 
a coat  of  pottery  varnish,  to  be  obtained  at  any  of  the 
color  stores. 

In  tlie  case  of  the  applied  artificial  flowers,  they 
should  he  heavily  painted  with,  say  four  or  five  coats  of 
white  paint  before  applying  the  color. 

Ornamental  articles  of  this  kind  cost  little  save  the 
labor,  and  will  well  repay  the  trouble  of  making. 


IMITATION  OF  MAJOLICA 

Cements  and  sealing  wax  are  useful  for  giving  to 
paper  and  wooden  articles  a hard  glaze,  resembling  that 
of  majolica  ware.  The  cwlindrical  vase  shown  in  the 
following  engraving  consists  of  a paper  mailing  tube 
3 inches  in  diameter,  and  6 inches  long,  furnished 
with  a pasteboard  bottom,  which  is  glued  in.  The 
inside  and  bottom  of  the  vase  are  provided  with  two  or 
three  coats  of  asphaltum  or  shellac  varnish  to  render 
it  waterproof.  The  outside  is  covered  Avith  jeweler’s 
cement  of  different  colors,  or  Avith  sealing  Avax,  or 
both.  The  bar  of  cement  or  wax  is  melted  at  the  end, 
and  applied  to  the  paper  cAdinder  in  the  same  manner 
as  it  is  applied  in  sealing  packages.  No  particular  care 
is  required  in  applying  the  Avax.  It  is,  liOAveA^er,  neces- 
sary that  the  edges  of  adjoining  patches  of  aa'Ux  be 


50 


.MKCIIAXICS  FOR  AMATEURS 


l)roni>lit  into  (‘oiiUK't  witli  (‘acli  oihvr  to  insure^  tlio  roin- 
plete  c()voriii!L»'  of  ilu^  ])a])(‘i‘.  In  tlie  (‘xa]n])l(^  sliowii  in 
tlie  eii<»Taviiii»',  olive  i>r(‘(‘n  j(^\v(‘le]‘'s  ('(Miaait  foians  the 
coveriiii;'  of  tlu^  lower  ])art  of  tli(‘  Tliis  is  blcaHlcMl 

into  (‘emeiit  (-oIoixmI  Avitli  VeiHhian  riMl  or  Iiulijui  red, 
and  the  (‘enient  at  the  to])  is  tl(H‘k(Ml  witli  y(^llow. 

The  mass  of  e(mient  is  laid  on  in  s])iral  lim^s,  and 
when  the  (‘overini»’  is  eoni])let(^,  th(^  yas(^  is  h(‘ld  over  a 

sniok(‘l(‘ss  tlani(‘,  sm'li  as 
that  of  a U>nns(m  burner 
or  ab'ohol  lamp,  or  it 
may  Ix^  h(*ld  over  a coal 
fire  until  the  cement 
fuses.  The  vase  should 
be  turned  in  such  a way 
as  to  cause  the  variously 
colored  cements  to  run 
into  each  other.  The 
vase  is  held  l)y  means  of 
a paper  tube  or  a stick 
inserted  in  its  open  end. 

Ornamentation  may  be 
applied  by  cutting 
leaves,  stems,  petals, 
etc.,  from  pieces  of  thick 
paper,  dippiug  them  in 
melted  cement  of  appro- 
priate color,  allowing 
th<*m  to  cool,  afterward 
arraiigiiig  them  upon  the  Yas(“;  finally  softening  the 
cement  of  I Ih'  vas(‘  and  I lie  ornament  by  holding  a dame 
ora  hot  iron  ovin-  lliem  iinlil  llie  c(‘ment  softens,  and 
the  oi-nainenis  are  allaclied.  ('are  is  reipiired  at  this 


Fig.  49.  Imitation  of  Majolica. 


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51 


point  to  avoid  the  complete  fusing  of  the  cement,  as 
this  would  spoil  the  job.  Care  is  also  required  to 
avoid  igniting  the  cement  or  wax,  as  it  is  nearly  impos- 
sible to  extinguish  it. 


STAINED  GLASS  AND  OBJECTS  OF  WIRE 

CLOTH 


A little  stained  glass  work  judiciously  distributed 
imparts  a bright  and  cheerful  air  to  the  house  by  intro- 
ducing a few  brilliant  colors  in  a legitimate  way,  where 
they  would  be  entirely  out  of  place  if  introduced  in 
draperies,  carpets,  or  furniture. 

It  is  an  easy  matter  to  make  stained  glass  work  after 
the  more  simple  designs.  It  onh^  requires  a knowledge 
of  the  use  of  the  glazier's  diamond,  or  the  very  efficient 


Fig.  50.  Details  of  the  Lead  Work. 


substitute  for  the  same  known  as  the  roller  glass  cut- 
ter, and  some  proficiency  in  the  use  of  the  soldering 
iron. 

The  colored  glass  can  be  procured  from  almost  any 
dealer,  and  for  the  grooved  lead  strips  in  which  the 
glass  is  set,  the  amateur  will  have  to  depend  on  the 
stained  glass  works.  Some  manufacturers  are  willing 


52 


JIOMK  ]\IKCMIA.\I(^S  Vi)\l  AMA1M^U1I8 


to  fiiniisli  it  ill  small  (jiiaiil  ii  i(‘S,  wliih*  ollua's  ar(^  ri^liic- 
taiit.  It  is  to  1)0  i'(\i>rott(Ml  that  lh(*r(‘  is  no  siin])l(‘  ^vay 
of  iiialviiii>  ili(‘So  stri])s.  Ev(*rv  slaiiKMl  i^lass  mainifac- 
tiiror  is  ])rovi(lo(l  with  a imu'hiiu^  hy  m(‘aiis  of  whi(‘h  he 
rolls  them  from  lari>(‘r  stri])s  of  about  th(‘  same  form, 
made  at  the  load  works,  ami  known  as  (‘am(‘S. 


Fig.  51.  Stained  Glass  Work  “ Crazy  ” Pattern. 


Two  kinds  of  load  strips  aro  gonorally  nsod  in  this 
kind  of  work,  on(‘  of  whic'h  is  shown  at  o,  in  Fig.  50. 
This  is  nai'row  and  con  vox,  and  woll  adaptod  for  small 
ourv(*s,  oiia-h^s,  (hv.  Tho  othor,  shown  at  in  the  same 
fignri^,  is  widen'  and  ihinnor  and  bedtor  adaptod  for 
straight  work.  At  in  tln^  saim^  fignro,  is  shown  the 
imdliod  of  allae'hing  oo])p(‘r  wire's  te)  tho  b'ael  fe)r  twist- 
ing are)nnel  I he*  re>els  whie'h  snp])e)rt  the*  Ave)rk,  as  slmwn 
at  (I. 

A el  rawing  e)f  the*  palte*rn  is  maele*  ni)e)n  ste)nt  papor, 


HOME  MECriAXICS  FOR  AMATEtlL’S 


63 


and  tlie  "work  is  besivm  by  cutting,'  tlie  ,nlass  according 
to  the  pattern,  fitting  tlie  lead  strips  and  soldering* 
them  at  tlieir  junction.  After  all  of  the  glass  pieces 
have  been  fitted  and  secnred,  the  Avork  is  turned  OA^er 
and  soldered  upon  the  other  side.  The  AA’ires  are  then 
attached  by  first  tinning  them  and  then  securing  them 
by  means  of  solder.  These  AA’ires  are  tAA’isted  aronnd 


Fig.  52.  A Leaded  Glass  Butterfly. 

iron  rods,  AAdiich  are  so  arranged  as  to  support  the  AA’ork. 

Small  pieces  aa  IU  not  require  the  iron  rods,  but  larger 

ones  are  liable  to  sag  and  buckle  of  their  oaa  ii  AA'eight. 

They  are  also  apt  to  be  blown  out  of  shape  by  a lieaA^y 

AA’iud.  The  easiest  pattern  to  ]>roduce  on  stained  glass 

is  that  shoAA’n  in  Fig.  51.  It  is  hardly  AAorthy  of  classi- 

* For  the  soldering,  an  ordinary  soldering  iron  is  employed,  and 
common  tinner’s  solder  is  used  in  fastening  the  joints.  Tallow  is 
used  as  flux.  A tallow  candle  is  commonly  employed  for  this  pur- 
pose. The  joint  to  be  soldered  is  rubbed  with  the  end  of  the 
candle,  and  the  solder  is  applied.  Of  course  the  iron  must  be  well 
tinned  and  hot,  and  the  touch  of  the  iron  upon  the  work  must  be 
very  quickly  and  dexterously  done. 


54 


HOME  MECllANJCS  EOli  AMATEURS 


fication  among  patterns,  l)iu  it  is  ])leasing  if  ])ro])(‘riy 
done.  Some  eare  is  ne(*(‘ssarv  to  secure  liaianony  of 
color,  but  there  is  little  cliance  of  failure  in  tliis  kind  of 
work. 

It  is  a common  practice  to  gild  over  the  h^ad  stri])s 
after  the  Avork  is  done,  l)y  means  of  gold  paint,  but  it  is 
a question  Avhether  it  is  any  im])royement  over  the  nat- 
ural color  of  the  lead,  espe(‘ially  in  work  exposed  to  the 
action  of  the  elements.  I^)r  some  indoor  Avork,  such 
as  fire  screens,  sash  screens,  lant(*rns.  lamp  shades,  et(*_ 
the  gilding  is  not  objectionable. 

The  screen  shoAvn  in  Fig.  52  is  not  difficult.  All  of 
the  glass  pieces  are  of  such  form  as  to  be  easily  cut,  and 
the  Avork  of  joining  the  lead  strii)s  is  quite  simple.  As 
to  colors,  it  Avould  be  Avell  to  folloAV  the  example  of  na- 
ture, or  in  any  case  to  select  such  as  Avill  harmonize.  It 
is  hardly  possible  to  produce  more  gorgeous  coloring 
Than  is  found  among  the  butterflies.  Green,  blue, 
greenish-blue,  red,  yelloAA^,  broAvu,  black  and  Avhite 
(opalescenU^  are  colors  from  Avhich  to  select  for  this 
object. 

The  Avire  frame  which  supports  the  glass  is  carried 
along  the  lead  strips  and  secured  by  solder.  The  an- 
tenme  are  of  Avire.  The  base  is  of  Avood,  neatly  stained 
and  polished. 

A class  of  ornamental  objects  may  be  made  from  Avire 
cloth  Avhich  rival  in  Ix^auty  any  kind  of  stained  glass 
work.  Figs.  53  and  54  are  examples  of  this  kind  of 
Avork. 

Tli(‘  wir(^  (‘loth  for  this  ])ur])()S(^  should  be  made  of 
firui  wir(*,  th(^  m(*sh  should  1)(‘  (‘oars(‘,  say  10  to  the  iiu'h, 
and,  mor(X)V(*]*,  tli(‘  clotli  should  b(‘  |)aint(‘d  and  alloAved 
to  dry  before  the  ornamental  AVork  is  applied.  The 


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55 


wire  cloth  is  sui^ported  a short  distance  from  a design 
drawn  on  paper  and  the  different  colors  are  introduced 
into  the  meshes  by  means  of  an  ordinary  writing  pen. 
A gelatine  solution  is  used  for  this  purpose.  It  should 
not  be  very  tliick,  and  it  must  be  kept  warm.  Ordi- 
nary, transparent  gelatine  maj^  be  colored  for  this  pur- 
pose by  adding’  aniline.  Colored  lacquers  answer  ad- 


Fig.  53.  Lamp  Shade. 


Fig.  54.  Hanging  Lantern 
of  Wire  Cloth. 


iiiirably  for  filling  the  squares.  Common  white  glue 
answers  very  well  for  filling  the  bodj'  of  the  design. 
The  beauty  of  this  kind  of  work  and  the  simplicity  of 
the  method  by  which  it  is  produced  recommend  it  for 
many  purposes. 

The  construction  of  the  frames  for  the  lamp  shade 
and  hanging  lantern  requires  some  mechanical  skill. 


5G 


UiniK  IMKCIIANICS  FOl?  AMATEURS 


Urobablv  ilio  aid  of  tlio  tiiisiiiitli  will  liav(‘  fo  Ix^  iii- 
vok(Ml  in  tli(‘S(^  ('as(‘s.  It  will  i)ay,  lio\v(*\(‘i',  as  ilu*  ai'ti- 
(‘les  will  Avell  r(‘])ay  iln^  1r()ul)l(‘  and  (‘X])(*ns(\ 

Tli(^  lian,i>in<»-  lantcaai,  54,  is  d(‘si^’n(*d  foi'  a ball. 
Tt  may  (-ontain  a k(‘r()S(ai(‘  lain]),  or  ili(‘  d(*vi(‘(‘  known 
as  tlu‘  ‘‘fairy  lain])/’  in  Avbirh  a lari^o  candl(‘  is  (an- 
l)loy(Ml  as  a sonrc'C  of  lit^lit. 

The  colored  cb(H*ks  in  (be  wire  ('loth  a])p(au'  lik(‘  |i>*enis 
when  illnniinated. 

An  expcaanient  showiiii^’  a phase  of  (‘apillarity  is  illus- 
trated by  the  annexed  enj>Tayings,  Avliich  give  patterns. 


Fig.  55.  Method  of  producing  Designs  on  Wire  Cloth. 

This  experiment  was  originally  intended  for  illus- 
ti'ating  tapestry  and  other  designs  formed  of  small 
s(jnai'(^s,  in  colors,  upon  the  screen;  bnt  it  has  another 
practical  a])])lication,  which  is  capable  of  considerable 
('X])ansion.  f'or  ])roj(H'tion,  a piece  of  brass  Avire  cloth, 
of  any  d(*sir(*d  m(‘sh,  say  from  12  to  20  to  the  inch, 
is  moiinl(Ml  in  a imhallic  franu'  to  ada])t  it  to  the  slide 
liohha'  of  lh(^  lanba'ii,  and  lh(‘  Avii'e  ('loth  is  ('oated 
lighlly  w ilh  la('(|n(a'  and  all()W(Ml  lo  dry. 

Th(‘  slid(*  jhns  pr(‘par(‘(l  is  ])la('(‘(l  in  Ihe  lant(a‘n  and 
fo('nse(l.  4di('  r(*(jni]x*(l  (l(‘sign  may  noAV  b(‘  tra('e(l  by 


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57 


means  of  a small  camel's  liaiv  Itimsli,  colored  inks  or 
aqueous  solutions  of  aniline  dyes  beiu}^'  used.  The 
small  squares  of  the  wire  chRli  are  filled  with  the  col- 
ored liquid,  and  show  as  colored  squares  upon  the 
scT’een.  Different  colors  may  he  placed  in  juxtaposi- 
tion without  liability  to  mixing;,  and  a design  traced 
Avithout  special  care  will  appear  regular  as  the  rec- 
tangular apertures  of  the  wire  cloth  control  the  differ- 
ent parts  of  the  design. 

The  colored  liquid  squares  are  retained  in  the  meshes 
of  the  wire  cloth  by  capillarity.  A damp  sponge  will 
remove  the  color,  so  that  the  experiment  may  be  re- 
peated as  often  as  desired.  In  this  experiment  the 
colored  squares  have  the  appearance  of  gems. 

These  designs  may  be  made  permanent  by  employ- 
ing solutions  of  colored  gelatine;  but  in  this  case  the 
squares  are  so  small  that  they  are  not  very  effective 
without  magnification.  Really  elegant  designs  may  be 
produced  in  this  way  for  lamp  shades,  windoAV  and  fire 
screens,  signs,  etc.,  as  described  above. 


JAPANESE  POKTIEKE  OR  CURTAIN 

There  is  a certain  delicacy  in  a curtain  made  of 
long  lashes  formed  of  straw  or  bamboo  and  beads 
Avhich  is  not  found  in  a fabric  of  any  kind.  Cur- 
tains of  this  sort  haA’e  been  largely  introduced  into 
this  country  of  late,  some  of  them  being  simple,  plain 
and  cheap,  Avhile  others  are  really  A-ery  elaborate  and, 
of  course,  correspondingly  expensiAm.  It  is  a very 
simple  matter  to  make  a curtain  of  this  class,  pro- 
vided the  materials  are  at  hand ; but  where  neither 
bamboo  nor  straAv  nor  beads  are  available,  it  becomes 


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more  diflieult.  Hut  a very  prescoitable  ciirlain  may 
he  made  from  paper,  wliicli  is  ohtaimil)l<‘  everywhere. 
'I'lie  large  engraving  shows  a very  simjile  ]»attern 
made  of  straws  of  dilfeirnt  lenglli,  and  glass  heads 
of  different  colors,  strnng  on  strong  thread  or  tine 
strong  twine. 

The  first  thing  to  1)0  done  toward  making  the  enr- 
tain  is  to  draw  a design  roughly  on  a sheet  of  pajXT, 
then  tie  a thread  in  a head  which  is  to  form  tin*  fin- 
ish of  the  lower  end  of  the  lash.  Then  the  head  is 


Fig.  56.  Method  for  making  Paper  Rolls. 


fastened  in  its  place  on  the  pattern  hy  driving  an 
ordinary  pin  throngh  it  into  the  hoard  or  table  be- 
neath. The  stringing  of  the  straws  and  heads  is  thus 
proce<‘ded  with  according  to  the  requirements  of  the 
])alt(‘rn. 

^N'lien  one  lash  is  finished,  its  upper  end  is  fastened 
on  till*  design  hy  an  ordinary  pin  driven  throngh  a 
knot  lied  in  the  (liread.  Th<‘  ne.xt  lash  in  order  is  pro- 
ceeded will)  in  1h(‘  same  manner,  and  so  on  nntil  the 
entire  series  of  lashes  is  don(^  A stout  string  is 


HOME  MECHANICS  FOR  AMATEURS 


6d 

stretclied  along  the  series  of  pins  by  which  the  upper 
ends  of  the  lashes  are  secured.  Each  thread  is  then 
tied  around  the  transvere  string.  If  desired,  the  threads 
may  be  spaced  by  beads  arranged  on  the  string  be- 
tween the  lashes.  As  all  the  knots  are  necessarily 
trimmed  close,  it  is  well  to  touch  each  knot  with  muci- 
lage. When  this  is  dry,  the  curtain  is  finished. 

A verv  handsome  curtain  mav  be  made  from  beads 
alone,  or  from  beads  and  plain  uncolored  straws,  or 
the  straws  may  be  d^’ed  different  colors  by  means 
of  aniline  dyes,  or  by  dipping  them  into  thin  colored 
lacquers. 

A curtain  or  portiere  of  bamboo  and  beads  is  made 
in  the  same  wav,  but  on  a larger  scale. 

It  is  easy  to  make  a good  imitation  of  these  curtains 
Avith  paper  tid)es  and  beads,  or  the  tubes  alone.  The 
manner  of  making  these  tubes  is  shown  in  Fig.  56.  The 
paper  from  wliich  the  tubes  are  made  should  not  be 
thicker  than  common  Avriting  paper.  It  may  be  either 
colored  or  Avhite.  The  best  results  Avill  be  secui’ed  by 
using  common  Avhite  Avriting  paper  and  coloring  the 
tubes  after  they  are  formed  and  dry,  by  means  of  thin 
broAvn  or  Avhite  shellac  Amrnish,  colored  Avith  pigments 
or  the  anilines. 

The  pieces  of  paper  from  which  the  tubes  are  made 
are  preferably  cut  in  trapezoidal  shape,  as  shoAvn  at 
1 and  2,  so  that  Avlien  the  tube  is  finished  it  Avill  liaA^e 
conical  ends,  as  shoAvn  at  5,  6,  and  7.  The  Avire  shoAvn 
at  3 is  used  as  a mandrel  upon  Avhich  to  roll  the  paper. 
The  larger  end  of  the  piece  of  paper  is  applied  to  the. 
Avire  Avhen  the  paper  is  rolled  up  in  the  manner  illus- 
trated at  4.  The  narrower  end  of  the  paper  is  gummed 
and  pressed  doAvn  closely,  Avhen  the  Avire  is  removed 


GO 


IIOMK  MKdIAXICS  I'oi;  AMA^ri-:(  i;s 


I-'k;.  r>7.  CurUun  lortiK'd  of  S(i-;iw,  Haniboo,  or  Pai)('r,  and  Beads. 


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61 


and  the  operation  is  repeated.  It  is  not  advantageons 
to  gmn  the  entire  surface  of  the  paper.  h''astening  at 
the  end  is  sufficient.  The  wire  used  as  a mandrel  should 
not  be  more  than  one-sixteenth  inch  in  diameter,  as 
too  large  a hole  through  the  rolls  allows  them  to  ar- 
range themselves  irregularly.  At  7 is  shown  a part  of 
a lash  formed  of  a long  tube,  a bead,  and  a short  tube. 

In  stringing  both  the  straws  and  the  paper  tubes  a 
long  slim  needle  will  be  required.  If  this  is  not  ob- 
tainable, a very  good  substitute  for  it  mav  be  made  bv 
forming  an  eye  or  loop  on  the  end  of  a thin  wire  of 
suitable  length. 

There  is  scarcely  any  limit  to  the  amount  of  labor 
that  may  be  expended  upon  an  article  of  this  kind; 
but  very  jdeasing  results  will  be  secured  by  the  adop- 
tion of  simple  designs,  which  may  be  easily  carried 
out. 

HEPDUSSE 

This  art,  as  practiced  bj^  the  silversmith  and  the  art- 
ist, is  almost  entirely  dependent  upon  the  manual  dex- 
terity of  the  operator.  A kind  of  repoussd  is  here  sug- 
gested which  depends  more  upon  appliances  than  skill. 
It  is  not,  however,  assumed  that  any  set  of  devices  can 
be  made  to  serve  in  lieu  of  taste  and  judgment. 

To  carry  out  this  method,  a piece  of  heavy  cotton 
lace,  or  heavy  open  work  fabric,  or  a piece  of  a basket 
may  be  glued  to  a block  of  hard  wood  to  serve  as  a sort 
of  die  for  producing  the  impression  in  the  metal.  The 
fabric  or  basket  work  is  not  only  attached  to  the 
block  by  means  of  glue,  but  its  finer  interstices  are 
filled  with  glue  so  as  to  present  a surface  resembling 
tlie  original  fabric  only  in  tlie  most  general  Avay. 


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Wilt'll  the  sine  is  perfi'cily  diy  iuid  hard,  Hk'  die  is 
laid  n])ion  a solid  l'ounda.l ion,  and  a [lii'cc*  of  very 
thin,  soft  copper  or  brass  is  secured  to  the  block  so 


Fig.  58.  Embossing  Thin  Metal. 


Fig.  59.  Basket  Pattern. 


iiH  to  covcM^  tli(‘  la(*(‘  as  sliowii  in  V\<^,  58.  A piece  of 
cork,  aI)oul  | inch  tln(‘k,  ajid  aboni  three  iindies  wide 
and  b oi*  8 inch(‘s  loni»j  is  laid  over  the  metal  and 


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63 


struck  with  a mallet,  as  shown.  The  cork  yields  suf- 

7 fL/ 

ficieiitly  to  push  the  metal  down  upon  the  die,  and 
cause  it  to  take  the  pattern  of  the  lace  or  whatever 
is  used  iu  forming  the  die.  A piece  of  rather  hard 
rubber  packing  will  answer  this  purpose  equally  as 
well  as  the  cork. 


Fig.  60.  Die  formed  of  Pasteboard. 

Designs  may  be  cut  from  strong  paper  or  pasteboard, 
and  glued  to  the  block.  Fig.  60  shows  a design  which 
may  be  reproduced  in  this  manner. 

In  Fig.  61  is  represented  a stencil  design  to  be  sawed 


()4  IIOMK  ]\IK(’IIA.\I('S  I'Olt  AiMA'I’KlMIS 


Fig.  61.  Stencil  Pattern. 


from  liard  wood.  The  lines  and  scrolls  are  discon- 
tinued in  places  so  as  to  cause  the  Avood  to  hold  to- 
If  it  is  desired  to  render  the  lines  continuous 
at  tlK^se  ])oints,  they  may  be  run  througli  with  a V- 
tool.  Tlie  dots  are  picked  out  with  a small  i»‘ouge  or 


Fjg.  (>2.  Rope  Pattern. 


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65 


the  point  of  a revolving  drill.  In  all  these  cases  the 
metal  is  attached  to  the  block  and  treated  as  shown 
in  Fig.  58. 

In  Fig.  62  is  represented  in  side  elevation  and  in 
section  a die  formed  of  a small  rope,  glued  in  a semi- 
circular groove  in  a bar  of  hard  wood.  The  embossing 
is  done  in  the  manner  before  described.  In  this  case 
a thick  piece  of  soft  rubber  is  preferable  to  cork  for 
forcing  the  metal  into  the  depression  of  the  die. 


Fig.  63.  Vase  formed  of  Embossed  Plates. 


Either  panels  or  continuous  strips  may  be  embossed 
in  the  manner  described,  and  these  are  to  be  used  iu 
making  frames,  vases,  and  various  ornamental  objects. 
If  the  metal  is  too  thin  for  a certain  case,  it  may  be 
strengthened  by  flowing  soft  solder  over  the  back  of  the 
plate  by  means  of  a soldering  iron. 

The  vase  shown  in  Fig.  63  is  formed  of  four  embossed 


66 


nom:  imkcmiaxk^s  you 


plates  of  (*op])er,  fasicauMl  lo  lli(‘  l)a(*k  of  four  vcu'lical 
brass  stri])s  by  sol(l(U‘,  11u‘  wliol(‘  Ixuiii^  s(‘(*ur(Ml  to  tli(‘ 
bottom  ])ie(‘(‘  in  tlH‘  saiiu^  inaiim*!'.  Tli(‘  l)ottom  (‘onsists 
of  a disk  of  eo])])er  sobbuxMl  in.  Tli(‘  bas(‘  is  foriiuMl  of  a 
brass  stove-pipe  collar  sobbuxMl  to  tln^  low(U‘  i)art  of  the 
body  of  the  vase.  The  rim  around  tlu^  to])  consists  of  a 
strip  emboss(Ml  on  tlu^  ro])(^  di(‘. 


Fig.  64.  A Bas-relief  in  Lead.  Copper,  or  Brass. 


As  to  finish,  anv  of  the  usual  methods  of  brass  finish- 
inj»‘  should  b(‘  (unployed.  This  vase  is  especially 
ada})t(Ml  for  containin<>  a jialni  or  other  lari^e  foliage 
[)lant.  Th(‘  c^arth  and  roots  may  Ix^  ])la(‘ed  directly 
in  th(^  vas(^  or  th(\v  may  Ix^  contaimxl  by  a pot  which  is 
(mcloscxl  by  th(‘  vas(*. 


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67 


It  is  obvious  that  vases  of  other  forms  and  other  em- 
bossed designs  may  be  made  on  this  plan. 

Bas-reliefs  may  easily  be  made  by  a method  which 
is  a modification  of  the  one  described.  Fig.  64  shows 
such  a relief,  and  Figs.  65  and  66  illustrate  the  tools 
required  for  making  it. 

To  the  Avooden  frame,  A,  is  fitted  a board,  B,  upon 


Fig.  65.  Frame  and  Form  for  making  the  Bas-reliefs. 

Avliicli  is  drawn  in  outline  the  design  which  is  to  be 
prodnced  in  relief.  The  board  may  be  of  pine  or  any 
close-grained  soft  wood  for  lead  work ; but  for  brass  or 
copper,  the  wood  should  be  hard.  To  the  frame.  A,  is 
attached  the  plate  of  metal  by  means  of  scretvs. 

The  board,  B,  is  removed  from  the  frame,  and  the 


68 


JLOME  MECHANICS  EOI{  AMATEURS 


portion  of  tlie  design  wlii(*li  is  to  form  tlu^  most  pi*omi- 
nent  feature  of  tlie  relief  is  suwcmI  out  of  the  board, 
when  tlie  latter  is  re])Ia(*ed  in  tlie  fi'aim^,  and  the  m(‘tal 
is  forced  into  the  ojiening  of  tlu^  hoard  by  pressing  upon 
the  snrfa('e  of  the  lead  o])])osit(^  the  hoh^  in  the  hoard,  or 
hy  pounding  it  hy  nutans  of  the  mallet,  (',  shown  in  hhg. 
()6.  As  soon  as  this  feature  is  ('omplete,  the  m^xt  in 
order  is  sawed  out  of  the  hoard,  and  the  operation  is 


Pig.  66.  Tools  for  Repousse. 

repeated  until  all  of  the  general  features  are  developed. 
The  pi'ogress  of  the  work  can  he  observed  at  any  time 
hy  removing  the  hoard,  11. 

The  f(^atiii‘(^s  may  he  corrected  or  modified  hy  work- 
ing from  (htli(a‘  side  of  the  plate  hy  means  of  the  con- 
v(*x  mall(‘t  and  tln^  wooden  ])nn(‘hes  and  chisels,  D 
(hhg.  ()(>j.  If  a snppoi't  is  di^sired  for  any  part  while 
tli(*  work  is  pi'ogi'(‘ssing,  a stout  hag  tilled  with  sand 
may  h(*  plac(‘d  uml(*r  lh(‘  jiai't.  A f(nv  very  small  hags, 


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69 


say  1 inch  or  inches  in  diameter,  will  be  found  con- 
venient. If  desired,  the  drapery  or  the  background 
may  be  chased  by  means  of  hard  Avood  or  metal  punches, 
bearing  on  their  faces  the  desired  figures. 

The  relief,  if  of  lead,  looks  well  with  an  antique  fin- 
ish. 


AN  EASY  METHOD  OF  PKODUCING  BAS- 


KELIEFS 


The  production  of  patterns  from  which  to  cast  orna- 
mental articles  is  confined  to  a class  of  artisans  who, 
by  long  experience  in  carving  and  modeling,  have  at- 
tained great  excellence  in  workmanship.  An  amateur, 
while  he  may  not  hope  to  attain  such  excellence,  and 


Fig.  67. 


Pig.  68. 


Bas-reliefs  in  Wax. 


cannot  expect  to  produce,  by  the  usual  processes  and 
with  limited  practice,  such  exquisite  articles  as  may  be 
seen  in  many  of  the  city  shop-Avindows,  may,  if  he  pos- 
sesses even  a modicum  of  artistic  taste  and  skill,  do 
something  in  that  direction. 


?0 


HOME  MECITANIOS  FOR  Ai\IATETJRS 


The  articles  required  to  carry  out  Hie  process  are 
some  thin  sheets  of  semi-transparent  wax,  a knife  hav- 
ing a narrow,  dull  blade,  and  the  ])rinted  or  drawn 
design  of  the  form  to  be  ]U‘oduced.  The  backing,  or  sur- 
face on  which  the  relief  is  made,  may  be  of  any  of  the 
materials  of  which  patterns  are  commonly  made. 


ITaving  given  the  backing  the  required  form  and 
located  thereon  the  position  of  the  relief,  a sheet  of  wax 
is  laid  over  the  design  and  the  extreme  outline  of  the 
figure  is  trac(‘d  on  the  surface  of  the  wax  with  a dull 
fioint.  The  wax  is  now  laid  upon  a smooth  board  and 
cut  upfin  the  line  just  mad('  with  the  knife,  the  blade 
being  slightly  warm.  The  wax  thus  cut  is  now  placed 


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71 


on  the  foundation  or  backing-,  and  fastened  by  heating 
the  knife  blade  quite  hot  and  touching  the  wax  at  sev- 
eral points,  so  as  to  cause  it  to  melt  and  adhere  to  the 


Pig.  71. 


Pig.  72. 

Patterns  for  Bas-reliefs. 


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72 


backing.  Siipi)()sing  Hiis  }»i(‘cc*  of  wax  to  liavc  the 
thickness  required  in  the  thinnest  i)ortion  of  tlie  relief, 
another  sheet  is  laid  upon  the  design  and  traced  within, 
and  a small  distance  from,  the  outline  of  the  design.  It 
is  ent  and  laid  ni>on  the  first  piece  and  made  to  adhere* 
hy  pressing  it  down  slightly. 

Another  sheet  of  wa.x  is  traced  within  the  outline  of 
the  second,  and  cut  and  lelaced  upon  the  two  already 
secured  to  the  hacking,  and  so  on  until  the  design  is 
produced  in  Avhat  might  he  termed  the  roKf/li.  This 
stage  is  illustrated  in  Figs.  GT  and  08,  which  are  re- 
spectively front  and  edge  views,  which  give  the  idea  of 
the  arrangement  of  the  several  sheets. 

After  the  sheets  are  i)laced  upon  one  another  in  the 
manner  first  observed,  the  edges  may  he  burnished 
down  hy  the  rounded  hack  of  the  knife,  or  by  any 
smooth,  rounded  implement,  which  must  he  slightly 
warmed. 

Superfluous  wax  maj^  be  removed  by  scraping  when 
cold,  and  indentations  and  interstices  may  be  filled  by 
adding  a little  wax.  A scroll  design  is  shown  in  Fig.  69. 

When  the  model  is  to  he  reproduced  in  metal  cast  in 
sand  moulds,  the  wax  should  be  slightly  varnished  with 
pattern  varnish ; but  when  the  design  is  to  he  produced 
in  plaster,  a mould  of  plaster  may  be  taken  from  the 
model  after  it  has  been  oiled. 

A bas-relief  may  be  made  in  this  way  from  a profile 
photograj)h  or  from  an  engraving. 

Tlie  juoeess  may  be  em])loyed  to  advantage  in  orna- 
menting i)atterns  for  the  coarser  and  heavier  kinds  of 
work. 

Figs.  70,  71,  and  72  represent  surfaces  ornamented  in 
this  manner. 


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73 


OKNAMENTAL  IRON  WORK  FORI  AMATEURS 

Although  artistic  wrought  iron  work  dates  from  very 
early  times,  it  was  never  more  popular  than  it  is  at 
present.  This  remark  applies  especially  to  movable 


Fig.  73.  Fig.  74. 

Iron  Lamp  Supports. 


articles  such  as  tables,  stands,  racks  of  various  kinds, 
fuel  baskets,  lamp  supports,  etc.  Many  of  these  arti- 
cles of  recent  manufacture  are  copies  of  antique  ob- 
jects, while  others  are  of  modern  design.  As  works  of 


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art  they  are  fully  equal,  if  not  superior,  to  the  speci- 
mens of  earlier  work. 

Now,  while  no  imitation  can  ev(“r  e<pial  the  oriijinal 
article,  it  must  be  admitted  that  imitations  often  prove 
very  satisfactory  to  those  who  can  neither  make  nor 
purchase  the  real  article. 

The  examples  of  iron  work  here  illustrated  are  styled 
imitations,  as  they  are  made  without  foryiiif!:,  i.  c.,  the 
iron  is  bent  either  cold  or  hot,  without  the  use  of  a 
hammer,  while  the  iron  bars  or  rods  maintain  their 
original  cross  section.  Anv  one  us(‘d  to  the  hammer 
and  anvil  can,  in  addition  to  the  curves,  apply  forced 
portions,  or  twist  and  forae  the  bars  used  in  the  scrolls. 


Fig.  75.  Jaw  for  Bending. 


The  only  special  tool  used  in  making  articles  of  this 
class  is  the  steel  jaw  shown  in  Fig.  75.  Its  slot  re- 
ceives the  bar  to  be  bent,  and  its  flattened  shank  is 
designed  to  be  held  in  an  iron  vise.  A scroll  is  formed 
by  placing  the  end  of  a bar  in  the  jaw,  and  winding  the 
bar  around  the  jaw  and  upon  itself,  afterward  unwind- 
ing the  bar  to  open  the  spiral  as  much  as  may  be  re- 
quired. After  the  scroll  is  complete,  the  inner  straight 
end  of  th(‘  bar  is  cut  off  by  jueans  of  a hack  saw.  The 
sharp  angles  may  also  b(‘  bent  by  the  use  of  the  jaw.  It 
will  facilitate  Ihe  opcuation  if  the  bar  is  heated  red  hot 
at  th(‘  point  of  Ixuiding.  A hammer  may  prove  useful 
in  this  part  of  the  operation. 


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75 


The  standard  of  the  lamp  support  consists  of  a piece 
of  gas  pipe.  The  feet  are  attached  by  means  of  screws, 
and  the  different  parts  of  the  iron  work  are  fastened 
together  by  means  of  small  screws  or  bolts. 

A rod  is  fitted  to  the  gas  pipe  and  has  at  its  upper 
end  a frame  or  cup  for  receiving  the  lamp.  A clamp- 
ing screw  passing  through  the  gas  pipe  holds  the  rod  at 
the  desired  height. 

An  easy  and  satisfactory  way  of  blacking  the  work 
after  it  is  finished  is  to  coat  it  with  a thin  varnish 
of  stick  or  seed  lac  cut  in  alcohol,  with  refined  lamp- 
black stirred  in  to  give  it  the  required  color.  The  var- 
nish should  be  made  quite  thin  to  avoid  any  gloss,  and 
should  be  strained  through  cheesecloth  or  similar 
material. 

It  is  obvious  that  grilles,  gates,  screens,  doors,  and 
other  objects  may  be  made  from  iron  in  this  way  with 
little  trouble  or  expense. 


SOME  THINGS  IN  WIKE 

There  is  scarcely  a limit  to  the  number  of  useful  and 
ornamental  things  that  can  be  made  from  wire.  Two 
examples  are  shown  in  the  engravings,  Figs.  76  and  77, 
representing  respectively  front  and  edge  views  of  a 
newspaper  and  magazine  holder  formed  of  a wooden 
back  and  wire  scrolls;  Fig.  78  showing  a small  Avire 
stand  or  card  receiA^er  having  a zylonite  top. 

The  scrolls  of  the  newspaper  holder  are  formed  of 
three-sixteenths  inch  square  brass  wire;  the  seA^eral 
pieces  being  bent  in  the  form  shown  and  held  in  place 
by  clips  of  the  same  material  soft-soldered  by  means  of 
a blowpipe.  The  overlapping  portions  of  the  scrolls 


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are  alse  soft  soldered.  Tlie  lower  pari  of  each  main 
scroll  is  held  by  a stronj;  stai)le  passiiiff  over  tin*  wire 
of  the  scroll  and  thronj>h  the  cleat  and  backboard  and 
clinched  on  the  back  of  the  board.  Tin*  threi*  wires  at 
the  center  of  each  scroll  are  prolonj'ed  below  the  cleat, 
as  shown,  to  form  a stop  for  limiting  the  swing  of  the 
scroll. 


Fig.  77.  Edge  View  of 
Newspaper  Holder. 


Fig.  76.  Newspaper  Holder. 


If  care  is  taken  in  soldering  the  clips,  the  brasswork 
will  re(jnire  little  preparation  for  laccpiering.  A stiff 
brush  charged  with  finely  jiowdered  jmniice  wet  with 
water  and  a|)|)li(‘d  vigorously  to  the  work  will  (piickly 
remove  all  stains,  and  will  give  the  work  a uniform  ap- 


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77 


pearauce.  The  backboard,  which  may  be  of  Avalnut, 
mahogany,  cherry,  oak,  ash,  or  mai^le,  should  be  var- 
nished and  well  rubbed  down  before  the  cleats  are 
applied. 

A holder  of  this  kind  will  receive  a large  number  of 
periodicals. 

The  wire  stand  or  card  receiver,  shown  in  Fig.  78,  is 


Fig.  78.  Wire  Stand  or  Card  Receiver. 

made  of  one-quarter  inch  or  three-eighths  inch  round 
brass  wire.  It  may  be  made  of  brass  tubing  three- 
eighths  inch  or  one-half  inch  outside  diameter  and 
rather  thick.  In  this  case  the  tubes  are  annealed  and 
filled  with  lead  before  bending.  The  lead  is  melted  out 


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HOME  MECHANICS  EOR  AMATEURS 


of  the  tubes  after  beu(liiif>.  Tlie  spirals  are  formed 
separately  by  wi‘a])piiif?  the  tulx'  oi-  wire  around  a 
eyliiidrical  bar  of  wood  or  iron  in  a closc^  helical  coil, 
then  stretcbinjj'  out  the  coils,  ])lacin<f  tluMii  toi^etber, 
as  shown.  They  are  then  clamped  on  a smaller  cylin- 
drical bar  and  their  upper  ends  are  twisted  together. 
Two  rings  surround  the  lower  ])art  of  the  spiial  and 
to  these  rings  are  secured  the  legs  lyv  means  of  sohh'r 
or  screws. 

Th(‘  small  rings  surrounding  the  legs  may  he  pur- 
chased and  secured  in  ])lace  by  solder. 

The  top  of  the  stand  consists  of  a disk  of  wood,  con- 
caved at  the  top  and  furnished  with  an  embossed  disk 
of  zylouite. 

The  under  surface  of  the  stand  top  is  provided  with 
a ])erforated  block,  which  fits  over  the  closely  twisted 
end  on  the  standard.  This  receiver  may  be  made  so 
small  as  to  stand  upon  a table,  or  it  may  be  made  of 
the  usual  table  height. 


SOME  THINGS  IN  BURNISHED  BRASS 

The  old  and  commendable  fashion  of  making  orna- 
mental objects  from  solid  hand-wrought  metal  is  being 
i-<‘viv(*d  to  a wonderful  extent.  Steel,  iron,  brass,  and 
co)»p(M-  are  wrought  into  a thousand  beautiful  and  use- 
ful forms,  and  the  gilded  and  tinsel  objects  of  recent 
days  are  now  s(,“t  aside  for  substantial  and  elegant  solid 
cast  and  hand-wrought  ornaments.  It  will  require  only 
a suggestion  to  set  the  amateur  mechanic  at  work  at 
this  sort  of  thing,  when  his  dwelling  will  soon  be 
adorned  with  articles  that  will  be  the  more  valuable 
for  having  b(*en  ])rodnc(‘d  at  home. 


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79 


Fig.  79.  A Brass  Easel, 


80 


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Brass  tubing  and  rods  of  round,  liexagonal  and  oc- 
tagonal section,  plain  and  ])erforat(“d  strips  of  different 
widths  and  tbicknesses,  half  round  and  s(‘nii-liexagonal 
strips,  and  brass  buttons,  knobs,  and  nails  of  various 
shapes,  may  be  purchased  so  that  the  amateur  will 


Fig.  80.  A Brass  Frame. 


readily  find  availahk^  materials  for  the  kind  of  work 
sii^j^ested.  llalf-ineh  s(inare  tubes,  strips  of  brass  half 
an  inch  by  on(*-sixth  of  an  iiK'li,  a lew  brass  buttons, 
and  a f(*w  knobs,  ar(‘  i'(M|uir(Ml  for  Ihe  easel  shown  in 


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81 


Fig.  79.  The  tubes  may  be  draw-filed,  then  finished 
with  the  different  grades  of  emery  paper  with  oil,  or 
they  may  be  polished  on  an  emery  wheel,  and  the  final 
finish  may  be  imparted  by  using  the  finest  French 
emery  paper  with  oil. 

When  two  tubes  cross  each  other  they  may  be  halved 


Fig.  81.  A Nautilus  Card  Receiver. 


together  precisely  as  in  wood  work,  and  may  be  fas- 
tened by  soldering  with  soft  solder. 

When  the  end  of  a tube  abuts  against  the  side  of  an- 
other tube  it  may  be  fastened  solid  enough  for  all 
practical  purposes  by  soft  soldering  by  means  of  a 
blowpipe.  Of  course  the  joint  may  be  brazed  or  sol- 


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derod  ■with  silver  solder,  loit  as  .ureat  streiiijth  is  not 
required,  it  is  nnnecessary  to  take  that  amount  of 
trouble. 

A very  good  ■way  of  fastening  is  to  solder  a plug  in 
the  end  of  the  tube  tliat  abuts  against  the  side  of 
another  tube,  and  to  put  a screw  ]at<‘rally  tlirougli  one 
into  the  plug  in  the  other.  In  this  case  it  is  well  to  l<*ave 
a slight  feather  on  op])osite  sides  of  the  abutting  tube 


Fig.  82.  A Brass  Clock. 


to  engage  the  corners  of  the  tube  to  which  it  is  at- 
tached. 

d'he  scrolls  should  he  attached  by  means  of  small 
screws.  "I'he  ]»auels  consist  of  thin  ])ieces  of  board  cov- 
ered will)  velv(‘l  or  ])lush  of  any  suitable  color.  They 
arc;  inserted  from  Hk*  hack,  and  are  provided  with  a 
nuTuher  of  large;  conve.x  nails.  The  su])port  for  the  pic- 
ture is  movahh*  up  and  d<»wn  on  the  side*  jeieces  of  the 


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83 


easel,  and  may  be  secured  at  any  desired  point  by  the 
milled  screws. 

The  frame  shown  in  Fig.  80  will  require  no  special 
description.  The  main  portion  of  it  is  made  of  square 
brass  tubing.  The  side  bars  are  made  of  round  brass 


Fig.  83.  A Brass  Table. 


rods  with  turned  end  pieces,  as  shown.  The  mat  of 
thin  wood  is  covered  with  velvet  or  plush.  The  picture 
and  glass  are  placed  behind  the  mat ; the  latter  is  pro- 
vided with  small  brass  ears  which  are  fastened  to  the 
back  of  the  frame  by  screws.  The  knobs  at  the  top, 


84 


llOiMI']  iMKGJlAiN'ICS  K()J{  AMATKlJItS 


bottom,  and  sides  of  the  frame  and  (‘asel  an*  turned  and 
attaelied  witli  solder. 

Fig.  81  shows  a tripod  stand  for  a nautilus  slu'll,  with 
an  ornamental  shell  ])laeed  below  it  in  tin*  eentm'  of  lln* 


cdoc'k  case,  consisting  of  an  ordinary  box  of  suitabb' 
size  covered  with  plush  or  velvet,  and  inclosed  in  a 
frame  of  brass. 

The  frame  is  built  up  in  the  manner  already  de- 
scribed from  s({uare  brass  tnbing  sjilit  lengthwise 
through  diagonally  opposite  corners.  The  lower  i)or- 


Fig.  84.  Examples  of  Paneling. 


tion  of  the  frame  consists  of  a wide  band  of  brass,  hav- 
ing a light  bead  soldered  to  its  upper  edge  and  a heavy 
bead  soldered  to  its  lower  edge.  A number  of  the  brass 
nails  are  placed  at  regular  intervals  and  soldered  at 
the  back  of  the  brass  base.  The  rail  at  the  top  is  made 
of  h(!xagonal  brass  tubing,  and  the  small  balusters  are 
turiKMl  from  brass  rods.  '^Ihe-  palette  and  brushes  are 
sawed  from  a plate  of  brass  and  attached  by  tacks 
soldered  to  the  back.  The  ])atch(“s  of  color  are  pro- 
duced by  diff(“i‘ent  colois  of  s<*aling  wax.  Four  brass 
nails  are  ins(‘rted  around  llu*  dial  to  relieve  the  blank 


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85 


spaces  on  the  plush.  The  clock  and  its  plush-covered 
case  inav  be  removed  from  the  brass  frame  when  it  is 
desired  to  clean  the  latter. 

The  table  shown  in  Fig.  83  is  of  the  same  general 
character  as  the  other  articles,  and  will  not,  therefore, 
need  particular  description.  The  central  portion  is  of 
three-quarters  inch  round  brass  tubing.  The  legs  are 
of  five-eighths  square  brass  tubing.  The  top  is  of 
wood,  plush-covered  and  fringed,  and  provided  with  a 
border  of  perforated  brass. 

Fig.  84  shows  different  kinds  of  panels.  The  balus- 
ters in  the  upper  one  are  turned ; in  the  two  lower  ones 
they  are  cut  from  sheet  metal. 

All  of  these  articles  may  be  lacquered,  but  they  pre- 
sent a more  elegant  appearance  if  the  metal  is  left  un- 
protected and  cleaned  occasionally  with  rottenstone 
and  oil. 

There  is  hardly  any  limit  to  the  number  of  pretty 
and  useful  articles  that  may  be  made  of  such  materials, 
with  the  expenditure  of  little  thought  and  labor. 

FORMING  PLASTER  OBJECTS 

It  is  sometimes  convenient  to  form  objects  of  cir- 
cular section  from  plaster  of  Paris.  This  is  a very  sim- 
ple operation,  requiring  only  A^ery  simple  tools  and 
apparatus.  An  iron  rod,  bent  at  one  end  to  form  a 
crank,  and  carrying  a conical  wooden  roller,  two 
notched  bars  of  wood  for  supporting  the  iron  rod,  and 
a pattern  made  from  a thin  piece  of  hard  wood,  com- 
prise the  outfit  for  making  these  articles.  The  rod  is 
held  in  its  bearings  in  the  bars  by  pins  inserted 
obliquely  in  holes  in  the  wood,  so  as  to  project  over 


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the  rod.  The  pattern  is  cut  so  that  its  ed^e  is  a profde 
of  one  side  of  the  article  to  be  made.  The  wood  slionld 
he  made  thin  on  the  workinc^  edf>;(‘.  The  patterns  may 
be  made  to  advantage  of  metal  backed  by  wood. 

The  conical  wooden  roller  should  be  flattened  on 
three  or  four  sides  to  prevent  tin*  ]>laster  from  tiirninfj 
aronnd  on  it.  The  roller  is  oiled  or  smeared  over  with 
grease,  and  a batter  of  plaster  of  Paris  is  prepared  by 
mixing  the  dry  plaster  with  water  to  the  consistency  of 
cream.  As  soon  as  the  plaster  begins  to  set  it  is  appli(‘d 
plenteously  to  the  roller,  and  while  the  rod  is  turned 


Fig.  85.  Forming  Plaster  Objects. 


by  means  of  the  crank  the  pattern  is  moved  forward 
toward  the  rod,  and  the  surplus  plaster  is  removed  by 
the  pattern  which  acts  as  a scraper,  xiny  deficiencies 
are  supplied  by  a new  application  of  the  batter. 

When  the  object  is  of  the  right  size  and  form,  the 
pattern  is  removed  and  cleaned,  and  again  applied  to 
th(‘  object,  the  latter  having  Ix'en  brushed  over  freely 
with  water.  This  giv(‘S  the  finishing  touch. 

j\fter  the  plaster  becomes  ])(“rf('ctly  dry  and  hard, 
llie  roller  is  knock(“d  out,  and  I In*  obj(“ct  is  subjected  to 


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8^ 


a dry  heat  at  a temperature  of  about  212  degrees  Fahr. 
for  an  hour  or  so.  It  is  then  brushed  over  with  thin 
glue  size  until  it  has  absorbed  as  much  as  possible, 
when  it  is  allowed  to  dry  for  several  days.  The  latter 
treatment  renders  the  plaster  hard  and  strong. 

The  final  operation  consists  in  painting,  lacquering 
or  bronzing  the  object,  as  taste  may  dictate. 


• ' • 


...IT  * 


?r. 


-1^.1 


— ^ 


PART  III. 

METAIi  WORKING 


SAWING  METALS 

GEEAT  DEAL  of  hard  labor  in  working 


metals  may  be  avoided  by  the  use  of  hack 
saws  and  jeweler’s  saws.  The  large  hack 
saw  has  a malleable  iron  frame  and  a handle 


and  tail  piece  which  will  revolve  so  as  to  adjust 
the  saw  to  any  desired  angle.  The  tail  piece  has  an 
adjusting  screw  by  which  the  tension  of  the  saw  may 
be  regulated.  Several  kinds  of  saws  can  be  used  in 
this  frame,  i.  e.,  saws  with  coarse  and  fine  teeth,  which 
are  set  more  or  less  according  to  the  kind  of  metal  on 
which  they  are  used.  These  saws  all  have  very  hard 
teeth,  but  the  main  portion  is  soft,  so  that  the  saw 
does  not  readily  break.  These  saws  are  cheap,  and 
when  one  becomes  dull  or  is  broken  it  is  replaced  by 
another.  They  are  so  hard  they  cannot  be  filed. 

The  next  saw  in  size  has  a heavy  wire  frame.  Slits 
are  cut  in  opposite  ends  of  the  frame  to  secure  the  saw, 
and  small  pins  extending  through  holes  in  the  ends  of 
the  saw  rest  in  notches  cut  in  the  frame.  The  spring 
of  the  frame  holds  the  saw  under  tension.  To  put  in  a 
new  saw,  the  ends  of  the  frame  are  sprung  inwardly 
with  considerable  pressure.  The  saws  for  this  frame 
are  also  hardened  on  the  toothed  edge,  the  remainder 
being  soft.  They  are  much  thinner  than  the  large  saws. 

The  smaller  saw  frame  is  adjustable  as  to  length  and 
is  designed  to  receive  very  small  saws  made  from  mate- 
rial like  watch  springs. 


[89] 


00 


|[()ME  MECHANICS  FOR  AMA'I'EIMIS 


This  saw  is  for  more  delicate  woik  than  Hie  oHkws. 
No  attempt  is  made  to  sharpen  them  with  a tile.  ,\  dull 
one  is  thrown  away  and  replaced  by  a mnv  one. 

There  are  many  kinds  of  work  in  which  a fjreat  d(‘al 
of  time  and  labor  may  be  saved  by  tin'  use  of  these 
saws;  for  example,  cuttin<^  off  iron,  steel  and  brass  bars 
and  tubes,  cutting  various  strajis  out  of  thick  sh(*et 
brass;  cutting  slots  in  work  when  reipiired.  They 
may  also  be  used  in  place  of  tiles  in  places  where  a file 
cannot  be  introduced. 


Nothing  is  more  useful  for  the  amatcMir  than  a knowl- 
edge of  the  art  of  soldering.  It  is  a very  simple  om*. 


Fig.  86.  Articles  used  in  Soldering. 


tlie  tools  required  are  inexpensive,  and  there  is  real 
satisfaction  in  doinii^  it  ratlier  tlian  being  delayed  to 
employ  a rc^gnlar  tinsmitli  or  other  meeliaiiie. 


of  eopi)(T,  j)oint(Hl  at  one  (aid  and  having  a large  wire 
s(‘r(‘\v(‘d  into  the  otlier  (aid,  tlie  wire  Ixang  provided 
witli  a woodiai  liandh*.  Soim^  soft  soliha'  will  be  re- 
(jiiirc'd,  say  a (jiiai'lia'  or  lialf  pound.  It  is  better  to  buy 


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91 


this  in  the  form  of  solder  wire,  but  it  can  be  readily 
made  by  melting  together  eqnal  parts  of  pure  tin  and 
pure  lead. 

To  carry  on  the  work  a small  box  of  pulverized  rosin 
and  a bottle  of  soldering  fluid  will  be  required. 

The  soldering  fluid  can  be  purchased.  It  is  readily 
made  by  filling  a small  bottle  half  full  of  hydrochloric 
acid.  (This  acid  must  be  handled  with  care  as  it  is 
poisonous  and  very  corrosive.)  Into  the  acid  drop  lit- 
tle strips  of  zinc,  a few  at  a time,  until  it  will  dissolve 
no  more.  This  operation  must  be  done  in  the  open  air, 
as  the  fumes  are  suffocating  and  injurious.  When  the 
boiling  of  the  acid  ceases  the  bottle  should  be  filled  up 
with  water  and  closed  with  a rubber  stopper.  In  addi- 
tion to  these  things  already  mentioned  a small  tin 
box  containing  a wet  cloth  will  be  required. 

Before  soldering  can  be  done  the  copper  must  be 
heated  so  that  it  will  melt  the  solder  readily.  Then 
the  pointed  end  must  be  cleaned  with  a file  and  a piece 
of  the  solder  wire  is  dipped  in  the  soldering  fluid. 
When  the  end  of  the  wire  wet  with  the  fluid  is  placed  in 
contact  with  the  side  of  the  hot  soldering  iron  it  will 
melt  and  the  soldering  fluid  will  cause  the  solder  to  ad- 
here to  the  copper.  This  may  be  repeated  until  the  four 
sides  of  the  pointed  end  are  covered  with  solder,  or 
“tinned”  as  the  smiths  have  it. 

To  solder,  the  joint  to  be  made  is  scraped  clean ; then 
a very  small  amount  of  the  soldering  fluid  is  applied 
if  the  work  to  be  soldered  is  iron  or  copper,  or  brass, 
but  if  it  is  bright  tin  a little  of  the  rosin  will  answer 
rather  better  than  the  acid.  The  iron  is  to  be  heated, 
not  too  hot,  however,  then  quickly  wiped  on  the  damp 
cloth  and  applied  to  the  solder,  to  take  up  a drop,  then 


1)2 


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l)laml  on  tlio  joinl  and  niovod  slowly  alonic,  allowinjj; 
the  solder  to  follow.  If  the  tinnini;;  is  hnrned  off  the 
solderinsj  iron,  it  innst  of  course  lx*  r(‘tinn<*d.  The 
secret  of  success  in  soldering  is  to  have  the  iron  just  hot 
enough,  and  to  have  the  surface  to  which  the  solder  is 
applied  very  clean. 

GRINDINCx  AND  POLTSITING 

Removing  surplus  metal  by  grinding,  sharpening 
tools,  and  smoothing  and  finishing  work  are  most  readi- 
ly accomplished  hy  the  amateur  by  means  of  emery 
wheels  of  various  degrees  of  fineness,  or  corundum  or 
carborundum  wheels  used  in  the  lathe.  If  a fine  lathe 
is  available,  the  wheels  may  be  carried  by  suitable  steel 
mandrels  mounted  between  the  lathe  centers,  or  bv  a 
single  mandrel  held  by  a chuck;  but  when  these  things 
are  not  available,  the  wheels  may  be  mounted  on  a hard 
wood  mandrel.  The  mandrel  has  a shoulder  against 
which  the  wheel  is  clamped  by  a wooden  collar,  and  a 
pin  or  key  passing  through  a hole  in  the  mandrel. 
Washers  of  leather  or  pasteboard  may  be  used  to  adapt 
the  mandrel  to  emery  wheels  of  different  thicknesses. 
In  selecting  an  emery  wheel,  one  should  be  chosen 
which  will  cut  freely  without  glazing.  Such  Avheels 
revolved  in  a lathe  cut  rapidly  and  serve  well  for  re- 
moving surplus  metal  and  for  sharpening  tools.  A 
rath(‘r  fiiui  wheel  is  preferable  to  a coarse  one  for  the 
latter  purfX)se. 

h'or  jxdishing,  a wheel  may  be  made  of  a disk  of  wood 
turned  in  the  lathe  and  cov(*red  on  its  peri])hery  or  side 
OT-  both  with  l<‘athei'.  Sole  leather  which  contains  no 
oil  or  gi'casc  is  tin*  Ix'st  for  tin*  ]Hir]X)se.  If  the  leather- 


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93 


covered  wheel  is  not  true  it  may  be  turned  off  in  the 
lathe  and  smoothed  with  fine  sandpaper.  The  leather 
on  the  edge  of  the  wheel  should  be  scarfed  and  lapped 
so  as  to  make  a smooth  joint. 

After  the  leather  is  properly  finished  it  should  be 
coated  witli  emery  of  the  degree  of  fineness  required. 
This  is  done  by  warming  the  wheel,  coating  it  with 
strong  glue  and  rolling  it  in  the  powdered  emery.  To 
insure  a good  job,  the  eineiy  itself  should  be  warm. 
Probably  the  best  way  to  secure  good  results  is  to 
spread  the  eiiiery^  out  on  a fiat  metal  plate  which  has 
been  heated.  The  leather-covered  wheels  are  very  use- 
ful. They  may  even  be  used  in  place  of  the  solid  emery 
wheel  in  many  kinds  of  work.  If  they"  are  used  care- 
fully they  will  last  a long  time  After  one  is  partly 
worn  it  is  even  more  useful  than  it  is  Avhen  new.  For 
polishing  steel  a leather-covered  wheel  of  the  kind  de- 
scribed charged  with  crocus  instead  of  emery  will  be 
required,  also  another  charged  with  fine  rouge  or  putty 
powder  for  a vei\v  fine  finish.  For  buffing  silver  and 
other  soft  metals  a wheel  of  chamois  skin  or  buck- 
skin drawn  over  a padding  of  soft  felt  and  tacked  at 
the  sides  of  the  wheel  will  be  found  valuable.  The  skin 
will  have  to  be  lapped  on  the  periphery  of  the  wheel, 
but  it  cannot  be  glued.  Fine  rouge  is  the  best  to  apply 
to  this  wheel.  For  polishing  irregular  surfaces  bristle 
brushes  must  be  used,  a coarse  brush  charged  with 
powdered  pumice  stone  for  doing  the  rougher  work; 
this  to  be  followed  by  a finer  brush  charged  with  tripoli 
or  whiting  and  Avater. 

The  brushes,  Avhich  have  wooden  hubs,  are  carried  by 
tapering  screAvs  held  in  the  lathe  chuck  or  inserted  in 
the  mandrel  in  place  of  one  of  the  centers. 


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SILVER  WORK 

Silver  is  not  a very  expensive  material  for  Die  manu- 
faetnre  of  small  objects,  and  it  is  easily  worked  and 
finished.  The  objects  when  finislied  have  an  intrinsic 
value,  and  if  the  effort  to  produce  a fim*  articl(*  results 
in  failure,  the  material  is  not  lost;  it  can  he  sold  as  old 
silver,  with  little  loss. 

The  eice,ravin,<>,  shows  articles  wliich  an  amateur  can 
make.  The  bonbon  dish  and  spoon  shown  in  the  illus- 
tration were  (piickly  made  by  an  amat(‘ur  silversmith. 


Pig.  87.  Examples  of  Silver  Work. 


It  is  first  folded  in  the  center,  then  opened  and  folded 
at  rif^ht  anolcs  to  the  first  fold ; then  opened  and  folded 
ajfain  pai'allel  with  the  first  fold,  and  so  on  until  the 
entire  surface  is  crossed  Avith  folds  about  three-fourths 
of  an  inch  ajiart.  The  ed,i>es  are  turned  up  all  around 
for  al)out  -g-  of  an  inch,  and  the  corners  are 
crimped  a littl(‘,  and  small  folds  are  made.  The  Avhole 
work  up  to  this  jioint  can  be  done  Avith  the  fingers 
alone.  The  folds  at  the  corners  are  hammered  down 


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with  a Avooden  mallet  while  the  sheet  rests  at  the  corner 
on  a round  support.  From  time  to  time  the  silver 
should  be  annealed,  i.  e.,  heated  to  a low  red  heat,  and 
plunged  into  cool  AAmter.  This  will  permit  of  bending 
the  silver  without  breaking  it. 

Little  folds  should  be  made  in  the  sides  at  the  upper 
edges  if  necessary,  to  allow  the  sides  to  be  straightened ; 
then  the  upper  edge  should  be  trimmed  off  with  shears, 
so  that  the  dish  is  the  same  height  all  around.  Then  a 
piece  of  holloAV  silver  wire  which  has  not  been  soldered 
is  opened  slightly  at  the  seam  by  drawing  a knife 
through  the  seam.  A piece  of  this  wire  long  enough 
to  reach  around  the  upper  edge  of  the  dish  is  slipped 
over  the  upper  edge  of  the  dish  and  soldered  at  differ- 
ent points,  with  silver  solder.  If  this  is  not  Avithin  the 
power  of  the  amateur,  he  may  attach  it  at  frequent  in- 
tervals by  means  of  A’ery  small  pieces  of  soft  solder 
melted  after  the  application  of  a A^ery  minute  quantity 
of  soldering  fluid,  by  holding  the  edge  of  the  dish  Avitli 
a pair  of  pliers  o\'er  a gas  flame  tAA'O  or  three  inches 
above  the  top  of  the  flame.  If  this  is  carefully  done,  the 
small  particles  of  solder  Avill  soak  into  the  joint  and 
become  invisible.  Across  the  corner  of  the  dish  is  se- 
cured a tree  limb  made  of  sih^er,  and  on  this  are  secured, 
the  birds.  The  siher  limb  is  made  bv  hammering  a 
stout  silA’er  Avire  into  a half-round  notch  in  the  end  of  a 
piece  of  steel,  grooA^es  being  formed  in  the  notch  to  give 
the  flattened  Avire  the  appearance  of  having  bark  on  it. 
The  birds  are  of  special  make,  used  for  other  purposes. 
If  the  amateur  sih^ersmith  desires  to  use  the  birds  he 
Avill  be  obliged  to  purchase  them,  as  they  cannot  readily 
be  made  by  one  having  no  experience  in  this  line.  They 
are  of  bronze  and  are  colored. 


9G 


UOMK  MKCTTANK'^S  FOIl  AMATFTKS 


Tliis  pai‘ti(‘iilar  disli  was  oxidizcMl  Ix^forc*  lli(‘  l)iT*ds 
wore  applicMl.  The  disli  was  oxidi/XMl  Iiy  iinin(‘rsiiii»-  it 
for  a few  miiintes  in  a solution  of  liisuljiliurcd  of  soda. 
It  was  tluui  wasliod  and  dricnl  and  lli(‘  oxid(‘  was  r(‘- 
nioved  from  tlio  proj(H'lini»  ])oidions  by  in(‘ans  of  a 
cdianiois  skin  (*liai\i]^ed  witli  roiyi»(‘.  Tliis  dish  may  rc^ad- 
ily  be  made  round,  (dli])ti('al,  or  trian,i>nlai*,  as  tast(‘ 
may  indicate.  It  is  w(dl  in  a easc^  lik(‘  this  to  try  the 
experiiiKUit  of  niakinf>^  the  dish  in  cojiper  or  soft  brass 
before  trying  silver. 


:\rETAL  FOOT  LATHE 

The  amateur  after  using  the  simple  wooden  lathe  will 
no  doubt  ask  for  something  more  jiretentions,  a lathe 
that  can  be  used  for  working  metals  in  various  ways, 
and  drilling  and  turning  hard  wood,  horn,  ivory,  rub- 
ber, etc.  Lathes  vary  in  price  from  |15  to  |50  and  up- 
ward. In  fact,  almost  any  amount  of  money  may  be 
invested  in  a foot  lathe  and  the  accessories  Avhich  can 
be  used  in  connection  with  it  to  great  advantage. 

The  better  way  to  proceed  is  to  purchase  a lathe 
complete,  with  fi\^-wheel,  treadle,  belt,  chucks  for  turn- 
ing wood,  centers  for  turning  metals,  a face  plate,  one 
or  two  lathe  dogs,  a drill  chuck,  three  or  four  hand 
tools  for  turning  brass  and  other  metals,  and  three  or 
fouT-  lools  for  turning  wood. 

Not  a gre^at  d(‘al  can  be  said  in  regard  to  the  various 
kinds  of  work  to  b(‘  done  on  a foot  lathe  of  this  kind. 
]\Ior(‘  can  b(‘  l(*a]‘n(‘d  in  a half  hour  by  the  observation 
of  a skilhxl  woi'kman  than  ('an  b(^  a('(|nired  by  a day’s 
])racti('(^,  or  by  a dudy  of  books.  However,  any  one 
having  a ni(*chaui('al  lui'ii  of  mind  ('an  tak(^  the  various 


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tools,  and  with  the  aid  of  a little  common  sense  can 
soon  master  the  art  of  hand  turning. 

After  practice  with  the  lathe  the  amateur  soon  finds 
that  other  tools  are  required,  and  he  will  either  make 
them  or  buy  them,  and  thus  gradually  add  to  his  outfit 
until  he  is  able  to  undertake  any  work  that  may  come 
along. 

To  turn  longer  pieces  of  metal  than  can  be  held  ad- 
vantageously in  the  chuck,  the  pieces  are  centered, 
drilled,  and  then  countersunk  to  fit  the  centers  of  the 
lathe,  one  of  which  is  iu  the  mandrel,  the  other  in  the 
tail-stock  spindle.  A lathe  dog  is  placed  on  one  end 
of  the  piece  of  metal  and  inserted  in  the  slot  in  the 
face  plate  of  the  lathe,  while  the  lathe  center  is  inserted 
in  the  countersunk  drill-hole  in  the  end  of  the  bar  to  be 
turned.  The  center  carried  by  the  tail-stock  is  brought 
forward  and  inserted.  The  tail-stock  is  then  made  fast 
to  the  lathe  bed,  and  the  center  is  adjusted  by  turning 
the  tail-stock  screw ; the  work  should  turn  easily  with- 
out chattering  and  the  center  should  be  oiled. 

It  is  a good  plan  to  finish  the  work  without  filing, 
but  the  file  and  emery  paper  may  be  used ; they  should 
be  used  with  care,  however,  as  they  are  liable  to  injure 
the  angles  and  finer  features  of  the  work.  A tool  will 
give  a fine  finish  on  steel  work  if  it  is  sharpened  on  a 
fine  oil  stone  and  the  work  is  wet  with  oil  or  some 
other  liquid ; even  saliva  is  often  made  use  of  with  good 
effect.  Brass  and  other  materials  softer  than  steel  are 
readily  turned  in  any  form  desired,  and  of  course  hard 
rubber  and  hard  and  soft  woods  are  still  more  easily 
worked. 

Turning  brass.  Babbitt  metal,  or  type  metal  is  not 
materially  different  from  turning  hard  wood,  The  tools 


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are  practically  tlie  same,  and  llie  metliods  are  the  same, 
hut  the  metal  tui'iiin!i>  is  dom*  at  a sonu'what  sl()AV(*r 
speed.  In  lh(‘  case*  of  nndals,  lln*  linishin<>  of  tlu*  shar[»- 
ening  of  flu*  turning  tools  is  done  on  an  oil  slom^  lo 
insure  the  smoolhiK'Ss  of  the  work.  The  work  should 
he  so  smoothly  done  that  no  final  finishing  will  he 
required.  If,  however,  brass  work  is  to  he  finished  it 
may  be  done  by  means  of  veuy  fine  emery  ])a])er  or 
cloth.  This  may  be  a])])li(“d  by  the  hand  or  strips  of  it 
may  be  glued  on  flat  or  convex  stri])s  of  wood  which  are 
used  in  the  same  manner  as  a file. 

The  amateur  cannot  expect  to  cut  screw  thn^ads  with 
chasers  as  readily  as  a skilled  mechanic,  but  he  can 
make  some  headway  with  practice  on  brass  and  hard 
wood.  Chasers  may  be  purchased  for  cutting  inside 
and  outside  threads.  The  chaser  is  moved  along  the 
lathe  rest  at  what  is  judged  to  be  the  speed  the  thread 
would  carry  it  along  if  already  cut  in  the  brass  or 
wood.  The  chaser  is  at  the  same  time  pressed  firmly 
on  the  rest  and  brought  into  engagement  with  the  ma- 
terial revolving  in  the  lathe. 

l\fake-shifts  are  not  to  be  generally  approved,  but 
the  writer  will  relate  a circumstance  which  came  to  his 
knowledge  some  years  ago  that  may  be  helpful  to  some 
one  caught  in  a similar  pr(*dicament. 

A lathe  was  available  but  no  sci’ew-cutting  tools  of 
any  kind  were  at  hand.  It  was  necessary  to  make  one 
or  two  fittings  for  a half-inch  gas  pipe.  Two  old  files 
were  found  and  anneal(>d,  and  in  the  end  of  one  were 
filed  with  an  ordinary  triangular  file  the  teeth  to  fit  the 
threads  of  tin*  gas  ]*ip(“.  In  flu*  side*  of  the  other  file 
were  filed  teeth  to  fit  th(‘  t(“(‘fh  of  the  first  chaser. 
Thes(‘  teeth  w<‘r(‘  filed  at  a slight  inclination  to  cor- 


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respond  roughly  with  the  pitch  of  the  screw  thread. 
These  chasers  were  hardened  and  tempered  and  used  to 
good  advantage  in  finishing  work  which  would  other- 
wise have  been  delayed  at  considerable  inconvenience. 


METAL-WORKII^G  ON  A LATHE 

INSTRUCTIONS  ABOUT  DRILLS  AND 
DRILLING 

An  ordinary  flat  drill  for  most  purposes  will  answer 
nearly,  if  not  quite,  as  well  as  a twist  drill.  It  is  not 
a difficult  matter  to  make  them,  since  we  have  such 
reliable  material  as  Stubs’  steel  wire  of  every  size.  The 
best  form  of  flat  drill  for  general  purposes  is  shown  in 
Figs.  88,  89,  and  90.  It  is  made  by  milling  or  filing  the 
opposite  sides  of  the  wire,  so  as  to  form  a bit  or  blade 
having  a thickness  equal  to  about  one-fourth  of  the 
diameter  of  the  wire.  The  angle  of  the  point  should  be 
90  degrees,  and  the  angle  of  its  cutting  edge  about  45 
degrees  for  most  uses.  For  a drill  for  very  hard  sub- 
stances these  angles  may  be  more  obtuse. 

Having  formed  the  drill,  it  should  be  hardened  by 
heating  it  to  a low  red  and  plunging  it  straight  down 
into  cool  (not  cold)  water.  In  case  of  a very  small 
drill,  it  may  be  held  in  the  flame  of  a gas  burner  or 
lamp  in  a pair  of  spring  nippers  over  a vessel  of  water. 
When  it  attains  the  required  degree  of  heat  it  may  be 
dropped  into  the  water. 

To  temper  for  most  cases,  the  drill,  after  being 
brightened  on  an  emery  wheel  or  piece  of  emery  paper, 
is  heated ; if  it  is  a small  one,  in  an  alcohol  or  gas  flame, 
until  its  color  at  the  point  runs  down  to  a brownish 


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yellow  vermin";  on  a ])urple.  If  the  drill  is  very  larjje 
it  nnvy  be  heated  ovei"  a forjj;(‘  fire*,  or  ov(‘r  a heavy  pi(‘C(‘ 
of  red-hot  iron.  If  the  drill  is  a very  small  om*,  it  may 
be  hardened  and  tem])ered  at  one  oi»eration  by  heatinj' 
to  a low  red  heat  and  plun^injj  it  imim'diately  into  a 
piece  of  beeswax. 


If  it  is  desired  to  have  the  point  of  the  drill  very  hard, 
without  being  liable  to  breakage,  its  temper  may  be 
drawn  In^  holding  its  point  in  pliers,  as  shown  in  Fig. 
88,  while  the  main  portion  is  held  over  a gas  flame. 
The  cool  jaws  of  the  pliers  prevent  the  point  from  be- 
coming heated. 

Another  method,  applicable  to  larger  drills,  is  to  em- 
ploy a notched  block  of  lead,  as  shown  in  Fig.  89.  The 
drill  in  this  case  is  driven  a short  distance  into  the 
load  before?  it  is  hardened;  then,  as  it  is  tempered,  it  is 
rej)Iaced  in  tin*  l(*ad  to  ])reserve  the  hardness  of  the 
cutting  edges  while  the  temper  is  drawn  in  the  other 
portions. 


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When  a drill  is  liardened  by  iramersiug  its  point  in 
mercury  instead  of  water,  it  acquires  a diamond-like 
liardness.  The  point  of  the  drill  just  described  is 
shown  in  perspective  and  in  section  at  D in  Fig.  90. 
The  drill  P is  similar  to  the  drill  D,  the  point  of  dif- 
ference being  a half-round  groove  along  each  face  ad- 
jacent to  the  cutting  edge.  This  device  gives  the  cut- 
ting edge  a more  acute  angle,  which  is  desirable  for 
some  kinds  of  work.  G is  a straight  drill  having  con- 
cave or  fluted  sides,  and  E is  the  well  known  twist 
drill.  The  drills,  G E,  are  shown  in  cross  section  in 
the  central  figure.  Twist  drills  of  recent  manufacture 
have  a central  longitudinal  line, which  locates  the  point 
in  grinding. 

The  best  ride  for  grinding  twist  drills  is  to  preserve 
as  nearly  as  possible  the  original  form.  The  ordinary 
pin  drill,  H,  is  used  for  counterboring,  a hole  being 
first  drilled  to  receive  the  pin.  The  drill  I is  employed 
to  give  an  ornamental  appearance  to  plates  in  which 
pivots  or  small  shafts  are  journaled,  as  in  clock  work. 
The  bottoming  drill,  J,  has  three  cutting  edges,  one 
upon  each  side,  and  a central  transverse  one  connecting 
the  other  two.  This  drill,  as  its  name  indicates,  is  de- 
signed to  make  a fiat  bottom  in  a drill  hole. 

The  pin  drill,  K,  which  is  shown  in  side  and  end 
views  in  Fig.  93  is  first  carefully  turned  and  afterward 
milled  with  the  rose  bit,  L,  producing  the  cutting  points 
or  lips,  which  are  afterward  beveled  with  a file.  This 
drill  is  used  for  boring  large  holes  in  sheet  metal,  a 
small  hole  being  drilled  first  to  receive  the  pin.  M is 
an  expansion  drill  for  the  same  purpose;  its  construc- 
tion will  be  readily  understood  from  the  engraving. 
The  spindle  is  mortised  to  receive  the  tool  carrying 


102  HOME  MECHANICS  EOK  AMATEUES 


arm,  which  is  scoured  in  the  mortise  by  a k(*y.  The 
lower  end  of  tlie  s])indle  is  bored  to  receive  tlie  drill, 
Avhich  also  forms  the  ]>in  for  <;ui<liii_n’  tin*  cutter. 

Wliile  uuiversal  chucks  are  recommended  for  holding 
drills,  another  form  of  chuck,  shown  in  Fig.  91,  may 
be  used  with  (‘qual  advantage.  Tt  consists  of  a main 


Fig.  90.  Forms  of  Drills. 


portion.  A,  wliicli  screws  on  tlie  lathe  spindle,  and  has 
a tajiering  thr(*aded  end  for  receiving  the  milled  nut,  B. 
The  thread(‘d  end  is  split  to  admit  of  its  contraction  as 
till'  nut,  B,  is  sci'ew(*d  on.  The  jijirt,  A,  is  bored  longi- 
tudinally to  i‘(‘c(‘i  v(‘ sect  ions,  C,  of  iron  or  steel  rod.  To 
lirepare  Ibis  clinck  for  holding  drills,  the  pieces,  C, 


HOME  MECHANICS  FOE  AMATEUES  103 


are  inserted  in  the  chuck,  centered  with  a pointed  tool, 
and  are  drilled  Avith  the  drill  Avith  AA'hich  they  are 
intended  to  be  used.  They  are  then  split  longitudinally 
with  a saAV  for  about  three-fourths  their  length.  The 
pieces,  C,  Avhen  once  prepared,  AA’ill  alAA'ays  ansAA^er  for 
the  same  sized  drill ; they  may  also  be  used  with  an 
ordinary  chuck  liaA'ing  a set  screw. 


Fig.  91.  Drill  Chuck. 


The  fluted  countersink,  O,  may  be  classed  among  the 
drills;  its  special  application  is  to  form  the  centers  of 
articles  to  be  turned.  It  has  the  same  form  as  the  lathe 
centers,  and  makes  a truly  circular  conical  hole,  provid- 
ing the  number  of  flukes  or  cutting  edges  is  odd. 

EA^ery  lathe  should  be  provided  with  a plate,  or  drill 
rest,  P,  fitted  to  the  tail  spindle,  for  supporting  plain 
AA’ork  while  drilling  it.  The  lathe  should  also  have  a 


Fig.  92.  Lathe,  with  Work  Support. 


HOME  MECHANICS  FOE  A]\rATEUES  105 


hinged  or  pivoted  rest,  Q,  which  niav  be  clamped  at  any 
desired  angle  for  drilling  irregular  work.  This  plate 
shonld  have  several  perforations  for  receiving  pins, 
for  preventing  the  work  from  slipping.  For  supporting 
cwlindrical  objects  to  be  drilled  transversely,  a fork, 
E,  is  inserted  in  the  tail  spindle. 


Fig.  93.  Drills  and  a Rose  Bit. 

As  to  the  matter  of  drilling,  little  need  be  said,  as 
nearly  everything  must  be  learned  by  experience;  how- 
ever, a few  points  may  be  mentioned.  The  work  should 
be  carried  forward  with  a.  regular  and  not  too  heavy 
pressure.  The  speed  of  the  drill  will  vary  with  the  ma- 
terial being  worked.  For  steel,  wrought  iron,  and  cop- 
per, the  speed  should  be  slow ; for  brass  and  cast  iron,  it 
may  be  quite  rapid.  In  drilling  steel  or  wrought  iron, 
oil  is  the  best  lubricant  for  the  drills ; in  drilling  glass, 
the  drill  should  be  wet  with  turpentine. 


lOO 


\\(n\K  ]\IK(  liANI(\S  VOW  jUIATVXW^ 


HINTS  (M)N(;fj{nin(}  (m:ntkihn(}  and 
sti:adyin(j 


To  conter  a (‘vliiidric'al  ])i(M‘(‘  of  iiuTal  i'(‘a(lily  and 
a(‘curat(dy  is  a very  sini])l(^  mat  tin'  wlnm  tin*  workman 
is  providcMl  with  tools  osjxM'ially  d(‘sii»n(Ml  foi*  th(‘  ])nr- 
poso,  and  it  is  not  ditticnlt  wlion  an  (miL»in(‘  latln^  or  (*v(*n 
an  engine  rest  is  availal)le  ; l)nt  to  do  it  (^asily  and  ])ro])- 
erly  in  an  ordinary  ])lain  foot  latlie  may  ])nzzle  some  of 


Fig.  94.  Centering  with  a Forked  Tool. 


the  amateur  meelianieians.  Although  some  of  these 
imdliods  ar(^  w(d]  knowip  they  Avill  neA^ertlieless  be  de- 
s(‘ril)(Ml  for  tlie  Ixuudit  of  some  who  may  require  the  in- 
format ion.  Th(‘  imdliod  of  (‘(mtering  shown  in  Fig.  94 
is  on(‘  of  1h(‘  most  (‘ommon  wlna-e  tlie  latlie  is  provided 
with  an  (mgim^  i'(*sl.  A fork(‘d  tool.  A,  is  (damped  in 
t1i(^  lool  post  in  smdi  a position  tliat  a lim^  drawn  from 
th(‘  point  of  th(‘  tail  (*(mt(‘r  will  biseet  the 


HOME  MECHANICS  FOE  AMATEUES 


107 


angle  of  tlie  fork.  A square  pointed  renter, 
G,  is  inserted  in  the  tail  spindle  and  moved 
against  the  end  of  the  rod  being  centered  with 


Fig.  95.  Centering. 


a slight  pressure,  the  tool.  A,  being  at  the  same 
time  moved  forward  by  the  screw  of  the  engine  rest  un- 
til the  rod  turns  smoothly  in  the  fork  and  the  square 


Fig.  96.  Centering  with  a Hand  Tool. 


pointed  center  has  found  the  center  of  the  rod;  the  tail 
spindle  is  then  moved  forward  until  the  cavity  is  suffi- 
ciently deep  to  permit  of  starting  the  center  drill.  The 


108 


HOME  MECHANICS  EOIf  AIMATEUHS 


aiiyle  of  sqiiare  ((“TitoT,  (I,  foi'  voiy  liai’d  inatorial, 
sliould  bo  a little  more  obtuse  tlian  that  shown  in  Fiji. 
97.  In  any  ease,  it  slionld  be  of  _<«(>od  niat(*i  ial  and  well 
tempered. 

In  Fif>-.  95  is  shown  a eenterinf>:  tool  wbieb  is  desif,nied 
to  take  the  place  of  the  engine  rc'st  and  fork  in  Fig.  94. 
The  part  R is  fitted  in  place  of  the  ordinary  tool  rest, 


and  the  .jaw.  Cl,  which  has  in  it  a V-shaped  notch,  is 
hinged  to  the  part  R at  I).  A screw,  E,  passes  throngh 
Hie  ni)j»ei'  end  of  the  part  R,  and  hears  against  the  jaw, 
(J.  After  what  has  aln^ady  been  said  in  connection 
with  the  engiTie  r<“st,  th<“  manner  of  using  this  con- 
trivance w'ill  l)(“  T'(*adily  nmh'rstood. 

[ti  I'dg.  9(1  the  hand  tool,  F,  is  employed  for  steadying 


HOME  MECHAxNTICS  FOR  AMATEURS 


109 


the  shaft  and  bringing  it  to  a center.  This  tool  is  bent 
to  form  a right-angled  notch  for  receiving  the  shaft, 
and  when  in  use  it  is  supported  by  the  tool  rest  after 
the  manner  of  an  ordinary  hand  turning  tool. 

Work  that  is  too  large  to  be  readily  centered  in  this 
manner  is  often  centered  apjjroximately  by  means  of 
the  universal  square,  as  shown  in  Fig.  98.  A diamet- 


Fig.  103. 


Steadying  Devices. 


rical  line  is  drawn  along  the  tongue  of  the  square, 
the  work  is  then  turned  through  a quarter  of  a revolu- 
tion, and  another  line  is  drawn.  The  intersection  of 
these  lines  will  be  the  center,  at  least  approximately. 


110  HOME  MECHANICS  EOK  AMATEUKS 


Fig.  104.  Turning  Long  Rods. 


HOME  MECHANICS  FOR  AMATEURS 


111 


This  point  may  now  be  marked  with  a center  punch, 
and  the  work  may  be  tested  in  a lathe.  If  it  is  found  to 
revolve  truly  on  the  centers  it  may  be  drilled,  otherwise 
the  center  must  be  corrected  with  the  center  punch,  and 
the  work  again  tested  in  the  lathe. 

After  centering  by  any  of  these  methods,  the  center 
must  be  drilled  and  countersunk  with  a suitable  tool, 
so  that  it  will  fit  the  lathe  center,  as  shown  in  Fig.  99. 
The  angle  of  the  lathe  centers  should  be  sixty  degrees. 
To  insure  uniformity  in  everything  pertaining  to  the 
centers,  the  center  gauge,  shown  in  Fig.  100,  should  be 
used  for  getting  the  required  angle  on  the  lathe  centers 
and  on  the  drills  used  in  centering. 

The  matter  of  steadying  the  long,  slender  rods  while 
l)eing  turned  in  the  lathe  is  often  perplexing. 

In  some  cases  it  may  be  done  tolerably  well  in  the 
manner  illustrated  in  Fig.  101.  The  fork,  H,  is  sup- 
ported by  the  standard,  I,  which  is  inserted  in  the 
socket  of  the  rest  support,  J.  The  device  shown  in  Fig. 
95  may  be  used  in  a similar  wav. 

Fig.  102  represents  a steady  rest,  the  construction  of 
which  will  hardly  need  explanation.  For  light  work  it 
may  be  made  of  wood ; the  upright  being  secured  to  the 
cross  piece,  L,  which  rests  upon  the  lathe  bed.  The 
slotted  pieces,  M,  are  adjustable  lengthwise  to  accom- 
modate the  size  and  position  of  the  shaft.  When  it  is 
required  to  support  a bar  which  is  not  round,  the  sleeve, 
N,  shown  in  Fig.  103,  is  employed.  It  slips  over  the 
shaft  and  revolves  in  the  steady  rest.  The  bar  is  cen- 
tered by  the  screws,  O. 

The  device  shown  in  Fig.  104  is  used  where  a hollow 
mandrel  lathe  is  not  at  hand.  A piece  of  gas  pipe,  Q, 
is  held  by  the  chuck,  P,  and  is  secured  by  a set  screw  in 


112  HOME  MECHANICS  EOli  AMA1MHIRS 


Hie  sleeve,  1>,  \vlii(*li  is  jouriialiMl  in  the  standard,  S, 
and  (‘arries  the  ehnek,  T.  Tliis  ai*ran<;(*in(Mit  may  also 
be  employed  for  tnrninj^  the  ends  of  loni^  rods  wherc^  it 
is  not  desirable  to  ])nt  them  r(\i»nlarly  on  the  centers  of 
the  lathe. 

CHUCKING 

In  spite  of  all  possible  a])pliances  to  be  used  in  a 
general  way  for  chucking  work  in  the  lathe,  a degriM^  of 
inventive  skill  is  often  rininired  to  accomplish  it  (piickly 


Fig.  105.  Chucking  a Metallic  Disk. 


and  securely.  Tln^  accompanying  (aits  are  designed  to 
aid  the  arnatcair  in  chn(*king,  but  after  all  is  said,  there 
is  a world  of  knowbalge  that  can  be  gained  by  experi- 
(aice  only. 


HOME  MECHANICS  FOR  AMATEURS 


113 


The  arrangement  of  a metal  disk  in  the  lathe  so  that 
it  can  be  turned  on  its  face,  and  upon  its  edge,  cannot 
well  be  accomplished  by  means  of  chucks;  for  this  pur- 
pose recourse  is  freqtiently  had  to  cement.  A good 


Pig.  106.  Chucking  a Spindle. 


cement  for  this  purpose  consists  of  Burgundy  pitch,  2 
pounds;  resin,  2 pounds;  yellow  wax,  2 ounces;  dried 
whiting,  2 pounds;  melt  together  the  pitch,  resin,  and 
wax,  and  stir  in  the  whiting. 


Pig.  107.  Chucking  Work  on  Pace  Plate. 


To  chuck  work  with  this  cement,  apply  a small  por- 
tion of  it  to  a face  plate  devoted  especially  to  this  pur- 
pose; heat  the  plate  so  that  the  cement  will  cover  the 


114 


HOME  MECHANICS  FOE  AMATEIJES 


fjroator  portion  of  its  snrfaco.  Tin*  plain  may  bo  al- 
lowed to  cool.  AVliomw(“r  it  is  (b'sirabb"'  to  clmck  a 
motallic  disk,  it  is  boated  and  plao(‘d  a<j;ainst  the  eenn'iit 
on  the  face  plate,  and  allowed  to  remain  until  tin* 
eement  begins  to  stiffen,  Avhen  a.  tool  having  a right- 
angled  notch  is  a])plied  to  the  edge  of  the  disk,  as  shown 
in  the  cut,  the  lathe  being  rotated  until,  by  Ihe^  com- 
pound action  of  the  tool  pressure  and  the  rotary  mo- 
tion, the  disk  becomes  jx'rff'ctly  true. 

To  chuck  a spindle  or  any  similar  object  a cement 
chuck  like  that  shown  in  section  in  Fig.  10(5  is  some- 
times used.  The  larger  ])ortion  is  screwed  on  the  lathe 
mandrel,  and  the  inner  end  of  the  hole  in  the  outer  por- 
tion terminates  conically.  The  hole  is  tilled  Avith 
cement,  and  the  article  to  be  chucked  is  warmed  and 
introduced.  It  mav  sometimes  be  necessary  to  heat  the 
chuck  Avith  an  alcohol  or  gas  flame.  The  lathe  is 
rotated,  and  the  spindle  is  held  lightly  until  it  becomes 
true  and  the  cement  begins  to  harden. 

To  remove  the  Avork  from  a cement  chuck,  it  must  be 
Avarmed  by  means  of  a lamp  or  otherAvise.  Most  of  the 
cement  adhering  to  the  AAork  may  be  Aviped  off  after 
heating  it;  AvhateA'er  remains  may  be  remoA^ed  with  a 
little  turpentine. 

A common  method  of  chucking  Avork  on  the  face  plate 
is  shown  in  Fig.  107 ; the  Avheel  is  temporarily  retained 
in  place  by  a jiointed  rod.  A,  Avhich  is  forced  against  the 
Avheel  by  the  tail  spindle.  A little  rapping  one  AA’ay  or 
the  other  readily  c(*nters  the  Avheel.  A piece  of  crayon 
h(*ld  in  a crayon  holder  suj>])orted  by  the  tool  rest  may 
be  used  to  discover  wbicb  side  of  the  Avheel  is  “out.” 
After  the  wh(*el  is  trued,  it  is  fast(m(“d  by  the  short  bars, 
15,  whose  outer  ends  rest  upon  any  convenient  blocking 


HOME  MECHANICS  FOE  AMATEUKS 


115 


while  they  are  drawn  by  the  bolts,  so  as  to  clamp  the 
wheel  firmly  to  the  face  plate. 

It  is  sometimes  preferable  to  use  the  yoke  shown  in 
Fig.  108  instead  of  the  bars  shown  in  Fig.  107 ; it  is 
placed  diametrically  across  the  wheel  and  secured  by 
two  bolts. 


Fig.  108.  Yoke. 

Fig.  109  represents  a chuck  consisting  of  a wooden 
disk,  c,  bored  to  receive  the  wooden  hoop,  d,  which  may 
be  forced  inward  by  the  common  wood  screws,  e,  which 
bear  upon  it.  This  chuck  is  useful  where  a consider- 
able number  of  similar  pieces  are  to  be  turned  or  bored. 


Fig.  109.  Wood  Chuck  for  Duplicate  Work. 


Fig.  110  represents  a simple  and  well  known  chuck. 
It  is  simply  a block  of  wood  secured  to  a face  plate  by 
a screw  center  and  turned  out  to  fit  the  work. 


116 


HOME  MECHANICS  EOII  AHATEUliS 


Fijj.  Ill  reprosonts  an  oasilv  made  clinck,  wliicli  is 
useful  for  lioldinj''  pluj^s  of  wood  to  be  turned  or  bored. 
It  consists  of  a ])iece  of  bard  wood  lifted  to  tlie  inaTnlrel, 
turned,  bored,  and  split  longitudinally,  as  shown  in  the 


Fig.  113. 


Chucking  Devices. 

onj]jravinj]j.  Its  outor  end  is  taj)('red,  and  to  it  is  fitted  a 
metallic  ring  that  serves  to  contract  the  chuck  when  it 
is  forced  on. 

Fig.  112  represents  a ta[)ei'(‘d  and  split  mandrel. 


HOME  MECHANICS  FOR  AMATEURS 


117 


which  may  be  either  of  metal  or  wood  according  to  the 
purpose  to  which  it  is  to  be  applied.  The  part  P is 
bored  conically  at  the  smaller  end  before  splitting,  and 
to  this  hole  is  fitted  the  conical  plug,  G,  which  being 
forced  in  expands  the  mandrel. 

In  Fig.  113  the  mandrel,  C,  has  permanently  attached 
to  it  the  cone,  D,  and  upon  it  is  placed  the  movable 


Fig.  114.  Fig.  115. 

Chucking  on  Angle  Plate.  Face  Plate  Jaw. 


cone,  E,  which  is  forced  against  the  work  held  between 
the  two  cones  by  a nut  which  turns  on  the  threaded  end 
of  the  mandrel. 

Tn  Fig.  114  the  manner  of  chucking  work  on  the 
angle  plate,  H,  is  shown  so  clearly  as  to  require  no 
explanation.  It  may  be  well,  however,  to  state  that 
when  the  work  is  rotated  rapidly  a counterbalance 


118  HOME  MECHANICS  FOR  AMATEURS 


sliould  1)0  attsiclicd  to  tlx*  face  plaU*  on  tin*  si<l(“  dia- 
inotrically  opposite  tlio  anj>l(‘  ])]at(*. 

Fig.  115  shows  a jaw  for  attacliiu'nit  to  tlie  face  plate*, 
wlii(‘h  consists  of  a right-angled  jeiece,  I,  a jaw,  J,  which 
has  two  guide  ])ins,  entering  holes  in  the  piece,  I,  and 
the  screw,  K,  which  j)asses  throngh  a tapjeed  hole  in 
the  piece,  I,  and  hears  against  the  jaw,  J.  The  ])iece,  I, 
has  a dowel,  a,  that  kee])s  it  from  turning,  and  a screw, 
b,  by  which  it  is  secured  to  the  face  plate. 


In  Figs,  lie  and  117  the  pin,  L,  is  fitted  to  the  face 
])late,  and  has  form(‘d  on  its  projecting  end  an  eccen- 
tric which  fits  the  jaw,  M.  It  has  also  a hexagonal  head 
for  r(‘c(*iving  tin*  wN'iicli  by  which  it  is  tnrned.  Three 
j)ins,  U,  are  fitb'd  to  the  fac(>  plat(‘,  which  is  (piite  thick, 
d'wo  of  I lie  ])ins  n(‘ed  not  be*  tiirnc'd  aftc'r  bc'ing  adjusted 
for  a certain  kind  of  work;  tin*  third  is  loosened  and 
turned  when  work  is  put  in  and  tak(‘n  out  of  the  lathe. 


HOME  MECHANICS  FOR  AMATEURS 


119 


After  the  work  is  clamped  tightly  by  turning  the  eccen- 
tric the  nut  on  the  back  of  the  face  plate  is  tightened. 

In  Fig.  118  is  shown  a type  of  the  most  convenient 
and  most  universally  useful  chuck  in  existence.  Its 


Fig.  118.  Scroll  Chuck. 


construction  and  use  are  so  well  known  as  to  need  no 
description.  • The  jaws  are  simultaneously  moved  to 
or  from  the  piece  of  metal  which  is  being  machined  by 
the  aid  of  a key.  Such  chucks  hold  drills  admirably. 

METAL  TURNING 

In  selecting  a lathe  an  amateur  may  exercise  more  or 
less  taste,  and  he  may  be  governed  somewhat  by  the 
length  of  his  purse;  the  same  is  true  in  the  matter  of 
chucks;  but  when  he  comes  to  the  selection  or  making 
of  turning  tools  he  must  conform  to  fundamental  prin- 
ciples ; he  must  profit  as  far  as  possible  by  the  experi- 
ence of  others,  and  will,  after  all,  find  enough  to  be 
learned  by  practice. 

Tools  of  almost  every  description  may  be  purchased 
at  reasonable  prices,  but  the  practice  of  making  one’s 


120 


HOME  MECHANIC'S  EOl!  AMATEURS 


own  tools  cannot  be  too  strongly  rcconinKMidcd.  Tt 
affords  a way  ont  of  many  an  cincrgcncy,  and  wlicri* 
time  is  not  too  valuable,  a saving  will  be  lealized.  A 
few  bars  of  fine  tool  steel,  a hammei-,  and  a small  anvil, 
are  all  that  are  reqnirc'd,  aside  from  fire  and  water. 
The  steel  sbonld  be  b(‘at(“d  to  a low  red,  and  sbajK'd 
with  as  little  hammering  as  ])ossible;  it  may  then  be  al- 
lowed to  cool  slowly,  when  it  may  be  filed  or  ground  to 


Metal  Lathe  Tools. 


give  it  tbe  required  form.  It  may  now  be  hardened  by 
healing  it  to  a cherry  red  and  plunging  it  straight  down 
into  clean  coo]  (not  too  cold)  water.  It  should  then  be 
I)olished  on  two  of  its  sides,  when  the  tem])er  may  be 
drawn  in  Ibe  flaiiK'  of  an  alcolnd  lamp  or  Bunsen  gas 
bniaier;  or,  if  these  are  not  conveni(‘nt,  a heated  bar  of 
iron  may  lx*  used  instead,  the  to<d  being  placc'd  in  con- 


HOME  MECHANICS  FOE  AMATEUES 


121 


tact  with  it  until  the  required  color  appears.  This  for 
tools  to  be  used  in  turning  steel,  iron,  and  brass  may  be 
a straw  color.  For  turning  wood  it  may  be  softer.  The 
main  point  to  be  observed  in  tempering  a tool  is  to  have 
it  as  hard  as  possible  without  danger  of  its  being 
broken  while  in  use.  By  a little  experiment  the  ama- 
teur will  be  able  to  suit  the  temper  of  his  tools  to  the 
work  in  hand. 


Fig.  122. 


16. 


Fig.  123, 


Metal  Lathe  Tools. 


In  the  engravings  accompanying  the  present  section 
a number  of  hand  turning  tools  are  shown,  also  a few 
tools  for  the  slide  rest.  These  tools  are  familiar  to  ma- 
chinists and  may  be  well  known  to  many  amateurs ; but 
we  give  them  for  the  benefit  of  those  who  are  unac- 
quainted with  them  and  for  the  sake  of  completeness  in 
this  volume. 


122  HOME  MECllAxNIlCS  FOE  AiMATHUHS 


No.  1,  Fig.  110,  is  tlie  ordinary  diamond  tool, 
made  from  a s(iuare  bar  of  sl(‘(‘l  gronnd  <liag- 
onally  so  as  to  give  it  two  similar  cutting  edges. 
This  tool  is  ])(‘i-lia])S  moi-e  genei'ally  useful  than 
any  of  the  others.  The  maniu'r  of  using  it  is 


Fig.  124.  Metal  Lathe  Tools. 


shown  in  Fig.  127 ; it  is  placed  on  the  tool  rest 
and  dexterously  moved  on  the  rest  as  a pivot,  caus- 
ing the  point  to  travel  in  a circular  path  along  the 
metal  in  the  lathe.  Of  course  only  a small  distance  is 
traveled  over  before  the  tool  is  moved  along  on  the 


Fig.  125.  Drill  and  Holder. 


rest.  After  a litth*  experience  it  tvill  he  found  that  by 
exercising  can*  a good  Job  in  plain  turning  may  be 
done  with  th<‘  tool. 

No.  2,  Fig.  12b,  shows  a shai-j)  V-sha])ed  tool  which 
will  be  found  useful  for  many  ]»urpos(“S.  No.  3 is  a 
V-shaped  tool  for  finishing  screw  thr<“ads.  Nos.  4 and 


HOME  MECHANICS  FOR  AMATEURS  123 


5 are  round-nosed  tools  for  concave  surfaces.  No.  6 
a square  tool  for  turning  convex  and  plane  surfaces. 
The  tool  shown  in  No.  7 should  be  made  right  and  left; 
it  is  useful  in  turning  brass,  ivory,  hard  wood,  etc.  No. 
8 is  a separating  tool.  No.  9 is  an  inside  tool,  ^vhich 
should  be  made  both  right  and  left,  and  its  point  may 
be  either  round,  V shaped  or  square. 

Fig.  128  shows  the  manner  of  holding  an  inside  tool. 
No.  10  is  a tool  for  making  curved  undercuts.  No.  11 


is  a representative  of  a large  class  of  tools  for  duplicat- 
ing a given  form. 

These  figures  represent  a series  of  tools  which  may  be 
varied  infinitely  to  adapt  them  to  different  purposes. 
The  user,  if  he  is  wide  awake,  is  not  long  in  discovering 
what  angle  to  give  the  cutting  edge,  what  shape  to  give 
the  point,  and  what  position  to  give  the  tool  in  relation 
to  the  work  to  be  done. 


124  HOME  MECHANICS  EOH  A:\tATEURS 


Having;  had  expeiicau'O  witli  liaiid  tools  it  rcMpiires 
only  a little  practice  and  observation  to  apply  the  same 
principles  to  slide  rest  tools. 

A few  exainph^s  of  tin's  class  of  tools  are  ij^iven.  No. 
12  is  the  ordinary  diamond  ])oint(*d  tool,  which  should 
be  made  rii»ht  and  left.  Tln^  (‘nttini»*  ed<»:(^  may  have 
a more  or  less  acute  angle,  according  to  the  work  to  be 


Fig.  127.  Using  the  Diamond  Tool. 


done,  and  the  inclined  or  front  end  of  the  tool  may  be 
slightly  s(piared  or  rounded,  according  to  the  work. 
Eig.  is  a se])arating  tool,  which  is  a little  wider  at 
th(‘  cutting  edge  than  anywhere  else,  so  that  it  will 
ch^ar  itself  as  it  is  forced  into  the  work. 

Eor  brass  this  tool  shonld  b(^  Ix^T^led  downward 
slightly.  Hy  giving  tln^  ])oint  tlu^  form  shown  in  No. 
d it  will  beadapt(*d  to  scn^w  cutting. 


HOME  MECHANICS  EOK  AMATEUES 


125 


No.  14  shows  an  inside  tool  for  the  slide  rest;  its 
point  may  be  modified  according  to  the  work  to  be 
done.  No.  15  is  a side  tool  for  squaring  the  ends  of 
shafts;  Nos.  16,  17,  18  and  19  represent  tools  for  brass; 
No.  16  is  a round-nosed  tool  for  brass,  No.  17  a V-shaped 
tool,  No.  18  a screw  thread  tool,  and  No.  19  a side  tool. 
In  boring,  whether  the  object  is  cored  or  not,  it  is  de- 
sirable, where  the  hole  is  not  too  large,  to  take  out  the 
first  cut  with  a drill.  The  drill  and  the  drill  holder 


for  the  purpose  is  shown  in  Fig.  125,  and  the  manner 
of  using  in  Fig.  126.  The  drill  holder,  B,  is  held  by 
a mortised  post  placed  in  the  rest  support.  The  slot  of 
the  drill  holder  is  placed  exactly  opposite  the  tail  cen- 
ter and  made  secure.  The  drill,  which  is  flat,  is  drilled 
to  receive  the  tail  center,  and  it  is  kept  from  turning 
by  the  holder,  and  is  kept  from  lateral  movement  and 
chattering  by  a wrench,  C,  which  is  turned  so  as  to 
bind  the  drill  in  the  slot  of  the  holder. 

The  relative  position  of  the  tool  and  work  is  shown 


126 


HOME  IVIECIIANICS  KOll  AM\TVA  \l^ 


in  Fig.  129.  Tlie  upper  eut  sliows  flu*  position  for  brass; 
the  next  for  iron  and  st(‘el ; tin*  tliii'd,  tln^  n^lativc^  posi- 
tion of  tlie  engine  rc^st  tool  and  its  work,  and  the  fonrtli 
the  ])osition  of  tlie  tool  for  soft  iindal  and  wood. 

In  all  of  these  eases  the  jioint  of  th(‘  tool  is  above 


Fig.  129.  Position  of  Cutting  Tools. 


the  center  of  the  work.  In  the  matter  of  the  adjustment 
of  the  tool,  as  well  as  in  all  other  operations  referred 
to,  experiment  is  recommended  as  the  best  means  of 
gaining  valuable  knowledge  in  the  matter  of  turning 
metals. 

CHASING  AND  KNURLING 

Among  the  multitude  of  operations  possible  with  a 
foot  lathe  jierhaps  none  is  more  vexatious  to  the  ama- 
t(mr  than  that  of  cutting  a good  screw  thread,  and  no 
a(‘(|uir(mient  is  more  valuable  than  to  be  able  to  chase 
a scnnv  thread  (^asily  and  ac(‘uratelj. 

Th(‘  ordinary  ('baser,  No.  1,  l^Mg.  130,  is  a simple 
tool  which  is  (uisily  made  wlum  one  has  the  hubs  for 
tin*  (lillei'cmt  siz(*s;  but  wanting  th(‘S(%  we  recommend 
tin*  purchase^  of  chas(n'S.  A blank  for  an  outside  ('baser 
is  shown  in  No.  2,  and  lh(‘  hub  used  iu  ('utting  the 
t(adh  is  r(*pres(Mil(Ml  in  Fig.  131.  The  latt(a*  (‘ousists 


PUTTING  ON  NEW  WARP  WITHOUT  RE-THREADING  THE 

HEDDLES. 

After  the  new  warp  is  on  the  beam  each  new  end  is  tied  to  a correspond- 
ing old  end. 


HOME  MECHANICS  FOR  AMATEURS 


127 


of  a piece  of  good  steel  having  a thread  of  the  desired 
pitch,  which  is  traversed  by  spiral  grooves  to  form 
cutting  edges.  This  tool  must  have  about  the  same 
temper  as  that  of  a tap.  When  used  it  is  placed  be- 
tween the  lathe  centers  and  revolved  at  a slow  speed, 


Fig.  130.  Chaser  and  Blank. 


Fig.  131.  Hub. 


Fig.  132.  Inside  Chaser. 


while  the  end  of  the  chaser  blank  is  held  against  it, 
being  at  the  same  time  supported  by  the  tool  rest.  The 
hub  should  be  oiled  during  the  cutting  process.  After 
cutting,  the  tool  is  hardened  and  tempered,  and  ground 
on  the  elevated  portion,  which  is  the  face,  and  smoothed 
on  the  back  which  slides  upon  the  tool  rest. 


128 


mniK  MECHANICS  foe  amateurs 


An  inside  (*liaser  is  sliown  in  V\g,  132,  tlie  l)lank 
from  wlii(*li  it  is  made  in  V\^^.  133.  f'or  (‘onvcmicaicc^ 
in  cnttiiifi^  the  teetli,  tlie  l)laidv  is  Ixait  at  ri<»lit  anf»l(‘s; 
after  (aittinji^  and  IxTore  liardeninj>*  it  is  strai!L»iitened. 


Pig.  134.  Starting  a Thread. 


The  manner  of  starting  a thread  for  chasing  is  shown 
in  Fig.  134,  the  tool  used  being  shown.  The  rest  is 
placed  a short  distance  from  the  work,  the  tool  is  held 


Fig.  135. 

firmly  upon  it,  and  while  tlie  work  revolves  with  a 
uniform  sjieiMl  th(^  tool  is  moved  dexterously  so  as  to 
mak(^  a sjiiral  lim^  on  iln^  work,  whi(*h  is  nearly,  if 
not  exactly,  of  lh(‘  sam(‘  jiitch  as  lh(‘  thread  to  be  cut. 


HOME  MECHANICS  FOR  AMATEURS 


129 


If  the  operator  is  fortunate  in  the  attempt,  it  will  be 
a simple  matter  to  start  the  chaser  and  move  it  along 
as  indicated  in  Fig.  136.  After  a little  practice  it  will 
in  most  cases  be  found  an  easy  matter  to  chase  threads 
without  first  starting  them  with  a pointed  tool.  It  is 
much  easier  to  chase  an  inside  thread  than  an  outside 
one.  A chaser  seldom  goes  wrong  when  working  on 
the  inside. 


Fig.  136.  Chasing  a Thread. 


A method  of  chasing  thimbles  is  shown  in  Fig.  137. 
The  threaded  thimble  which  forms  the  guide  screw  is 
driven  on  the  larger  end  of  the  tapering  mandrel ; the 
thimble  on  which  the  thread  is  to  be  cut  is  placed  on 
the  smaller  end  of  the  mandrel.  One  arm  of  the  forked 
tool  has  a vertical  chisel  edge,  which  engages  the  guide 
screw  ; the  other  arm  has  a chasing  point  which  cuts 


JIOME  MECHANICS  FOR  A:MA'1'EURS 


130 


the  thread.  Tlie  chisel  <‘(1,i>e  is  first  l)r()U,iili(  into  eii- 
ji'af'eineiit  with  the  jiu'de  screw,  tlie,  ])oint  is  tlicii 
(juickly  br()n_i>ht  apiinst  the  work  with  more  or  ](‘ss 
])rcssnre.  After  tlie  thread  is  well  startcil  it  may  he 
finished  with  an  ordinary  chaser  or  with  a ])ointcd 
tool. 


Fig.  137,  Chasing  Thimbles. 


138  sliow8  a metliod  of  starting  an  inside  thread. 
Tlie  cliascT*  lias  a tracing  edge  that  follows  the  guide 
scrcnv  projcM'ting  from  the  center  of  the  chuck,  and  a 
('lining  point  that  forms  the  thread.  Fig.  139  shows 
I li(‘  tool  in  d(‘tail. 

Tlir(‘ads  cut  by  a ('liascn'  without  S(>me  kind  of  a 
giiid(^  to  start  tlnmi  ai'(‘  oft  cm  niorc^  or  less  ('rooked  or 
dninlom.  1'o  cori'(*(‘t  such  thr(‘ads  and  in  (mtting  large 
ilir(*ads,  tln^  doclor,  shown  in  h'ig.  140,  is  sometimes 


HOME  MECHANICS  EOK  AMATEURS 


131 


eiiiplojed.  The  folloAver  opposite  the  chaser  is  moved, 
up  by  the  thumbscrew  as  the  thread  deepens. 

The  most  expensive,  and  at  the  same  time  the  most 
desirable,  contrivance  for  chasing-  screw  threads  is 
shown  in  Fig.  141.  A casting  fitted  to  the  lathe  bed 
has  two  ears,  which  are  bored  to  receive  the  round 


Pig.  138. 


Fig.  139.  Chasing  Inside  Threads. 


sliding  rod  carrying  the  tool  holder  and  tracer.  The 
tool  holder  is  placed  on  the  sliding  rod  between  the  two 
ears,  and  it  carries  a well-fitted  screw,  which  bears 
against  the  horizontal  bar  supported  by  two  square 
posts,  which  form  a part  of  the  main  casting.  This 
bar  forms  a guide  which  may  be  adjusted  within  nar- 
row limits  by  the  screw  seen  in  the  right  hand  post. 


Tlio  latlie  is  ])! ovided  wiili  a fa(‘(‘  plate*  lia\iiii»;  a loiiij 
boss  aia‘aiii>(*d  to  r(*(‘(*i\(^  tliiiid)l(*s  liaviiii;-  l(*adiiii»’ 
threads  of  different  pitedies  cut  on  th(*ni.  Tin*  traeaiiji^ 


thimbles,  and  is  ea])al)le  of  yi(ddini»  to  admit  of  mov- 
inj»‘  the  (mttinf>'  tool  foi'ward  ai^ainst  tin*  obj(*('t  l)(*iiiij; 
tliread(*d;  bnt  beini»'  w(dl  fitted  to  tlie  mortise*  in  tlio 
arm  it  e'anne)t  me)ye  late*rally  Ayitlie)nt  e‘arryini»‘  tliei 
slielini»“  re)el  anel  all  attaeduMl  te)  it.  The*  tra(*in<»  te)e)l  is 
sle)tted  te)  ree(*iye  a ])in  \yhie-h  ])asse*s  transye*i‘se*ly 


Fig.  140.  A Doctor  for  Cutting  Large  Threads, 


throiiftli  tlie  heael  of  the  tracing  arm,  and  in  the  slot  is 
])laceel  a spiral  si)ring  which  tends  to  throw  the  tracer 
fe)rwarel. 

The*  e)peratie)n  of  this  deyice  neeels  ne)  special  ex- 
planatie)!!.  The  arm  that  carries  the  entting  toed  is 
me)ye*el  fe)rwarel  until  its  aeljnsting  screw  strikes  the 
he)rize)nta1  gniele*  bai*;  the*  trae-ing  te)e)l  at  the  same 
time*  e*ngage*s  the*  le*aeling  s(*re*w  anel  e‘arrie*s  all  tdrward. 
\\die*n  I he*  je)e)l  has  ti‘aye*le*el  as  far  as  de*sirable  it  is 
elraw  n bae*k  anel  reitnrne*el  te)  ils  e)]dginal  ])e)sitie)n.  With 
I his  loe)l  lhre*aels  may  be*  emt  e)n  e*ithe*i'  e'yl inelrie'al  or 
ta[)e*i‘iiig  we)r‘k. 


HOME  MECTTAXirS  FOE  Al\rATEITBS 


133 


Fig.  141.  A Good  Method  for  Cutting  Threads. 


134 


IIOMK  MKCniANK^S  KOII  AMAIM^UKS 


It  is  S()in(4i]n(‘S  (l(‘sii'al)l(‘  io  form  s])iral  ^roov(*s  in 
tlio  fa(‘(^  of  a disk;  tliis  may  a(*(‘om])lisli(*(l  in  (^xa(*tly 
tlm  same  manma'  as  in  the  (*as(^  of  ili(‘  (‘vlimli'icad  work. 
Tlu^  nudliod  of  (loin<»  if  is  illnsfraf(Ml  by  142. 

Knurls  of  various  ])ai terns  ai'(‘  sliown  in  f'i^.  14‘k 
These  are  eni])loy(Ml  in  ^d)(mdinjL»*;’ ^bnillinjL>:,”  or  knurl- 
iiic^tlie  lieads  of  s(*rews,  the  liandles  of  small  tools,  (dc. 
The  manner  of  usini]^  this  tool  is  shown  in  145. 


Fig.  142.  Cutting  Spiral  Grooves. 


The  knurl  is  placed  between  the  forks  of  a holder  and 
upon  a j)in  that  passes  through  the  fork,  and  is  held 
with  eonsiderable  pressure  against  the  work  as  it  re- 
volves. 

Th(^  knurls  shown  in  hdg.  144  are  easilv  made. 
All  that  is  r(*(piir(‘d  is  a hub  something  like  that 
shown  in  hig.  12>1.  This  is  ])la(‘(‘d  b(‘twe(m  the  centers 
of  lh(‘  lath(%  and  1h(^  knni'l  blank  is  brought  in  (‘ontacd 
with  it  and  aIlow(Ml  io  n^viAvi^  in  a holder  su])ported 


HOME  MECHAHTOS  FOE  AiAIATEUES 


135 


bj  the  tool  rest.  The  straight  blank  is  moved  np  and 
down  until  every  part  of  the  surfaee  is  cut  in  the  same 
way.  The  concave  blanks  cannot  be  moved,  but  the 


Fig.  143.  Knurls. 


Fin.  144,  Examples  of  Knurling. 


Fig.  145.  Knurling. 

Ilub  should  fit  the  hollow  of  the  face  of  the  blank.  The 
fancy  knurl  showu  in  Fig.  143  must  be  made  by  a die 
sinker.  Fig.  144  represents  examples  of  knurling 
done  with  knurls  shown  in  the  preceding  figure. 


mniK  MKCIIAXK^S  Foil  A.MA1M^i:ilS 


KiG 


KOTAKiV  (U  TTKKS 

The  sayiiii»’  of  iiiahaGals  and  j)ati(‘iic(^,  hy 

tlie  oiuployinoiil  of  siuGi  rotai'y  (aitt(a‘s  as  may  1k‘ 
])rofital)ly  iis(m1  in  (•oiin(‘(‘tion  Ayiili  a foot  lalln^,  can 
liardly  be  a])])r(M‘iat(Ml  l)y  oin^  wlio  lias  iH^ycn*  att(*in])t(‘d 
to  use  this  (Gass  of  tools.  It  is  astonishin,i;  lio\y  ininGi 
y(‘ry  hard  labor  may  be  say(Ml  by  im^ans  of  a small 


Fig.  146.  Metal  Circular  Saw. 


circular  saw  like  that  shown  in  Fig.  140.  This  tool, 
lik(^  maiiA^  of  the  others  described  in  this  section, 
can,  in  most  instances,  be  piii’chased  cheaper  than  it 
can  be  made,  and  the  chances  are  in  faA’or  of  its  being 
a more  perfect  article.  However,  it  is  not  so  difficnlt 
to  make  as  one  might  suppose.  A piece  of  sheet  steel 
may  he  clincked  ipion  the  face  plate,  or  on  a Avooden 
block  attached  to  the  face  jdate,  Avhere  it  may  he  bored 
lo  fit  tin;  saw  mandi'el,  and  cnt  in  circnlar  form  hy 
means  of  a suitable  hand  tool.  It  may  then  he  placed 
npon  fhe  inandi'cl  and  tnrm'd  trm*,  and  it  is  Avell 
enoimh  lo  make  it  a,  little  Ihinmn*  in  flu*  middle  than 
nl  lln^  ])(*ri|)h(*ry. 

1di(i!‘(‘  nr(^  s(*v(*ral  mcGhods  of  forming  ilu^  t(H41i  on 
n circnlar  saw.  1 1 may  lx*  spac'cd  and  lilcd,  or  it  may 


HOME  MECHANICS  FOR  AMATEURS 


i:h 


be  knurled,  as  sliown  in  Fig.  147,  and  then  filed,  leaving 
every  third  or  fourth  tooth  formed  by  the  knurl;  oi* 
it  may,  for  some  purposes,  be  knurled  and  not  filed 


at  all.  Another  way  of  forming  the  teeth  is  to  employ 
a hub,  sometliiug  like  that  used  in  making  chasers,  as 
shown  in  Fig.  148.  The  difference  between  this  hub 
and  the  other  one  referred  to,  is  that  the  thread  has 
one  straight  side  corresponding  with  the  radial  side  of 


138  IIOAFK  IMKCIIAXK^S  KOI?  AMA^M^TIJS 

tlie  tootli.  Tli(‘  blank  fi'oin  wliicli  IIk*  saw  is  nnub*  is 
])la(‘e(l  on  a stnd  ])r()j(M-lin^  fi'oin  a liandb*  niacb*  sjx*- 
(dally  for  tln^  ])nr])os(^,  and  liavini;'  a i'onnd(*d  (mkI  wlii(‘li 
sn])])orts  tlu^  of  tin*  l)laidv,  as  th(‘  ai'(^  foiaiKMl 

by  tlie  (Mitters  on  iln‘  linl). 


Fig.  149.  Small  Saw. 


The  saWj  after  tlie  teeth  ai'(‘  fornuMl,  may  Ix^  liaixbmed 
and  teni])ered  l)y  li(‘atin:L>  it  slowly  until  it  attains  a 
cherry  red,  and  plnn<>ini>'  it  straii>ht  down  (Mli»(^wis("  into 
cool,  clean  water.  On  reinovino*  it  from  the  Avatcn* 
it  should  be  dried  and  cleaned  with  a ])i(M'(^  of  (mi(M*y 
paper,  and  its  temper  drawn  to  a ])nrple  over  a T>nn- 
sen  i»as  flame,  over  the  flame  of  an  alcohol  lamp  or 
over  a hot  plate  of  iron.  The  small  saw  shown  in  Fig. 
149  is  easily  made  from  a rod  of  tine  steel.  It  is  very 
nsefnl  for  slitting  sheet  brass  and  tubes,  slotting  small 
shafts,  nicking  screws,  etc.  Being  quite  small  it  has 


Pig.  150.  Mandrel.  Fig.  151.  Cutter. 

1h(*  advaniag(^  of  having  few  tcxhli  to  kee])  in  order,  and 
il  may  Ix^  niad(‘  hard(‘r  than  1hos(^  of  largiT  diameter. 
A s(iri('S  of  IIkmii,  varying  in  dianudcu'  fi'om  one-eighth 
to  I hr(X‘-(4ghl  hs  of  an  inch,  and  varying  ('onsidei'ably 
in  lhickn(*ss,  will  IxM'onnd  v(‘ry  (M)nv(mi(mt. 


HOME  MECHANICS  FOE  AMATEHES 


139 


These  cutters  or  saws,  witli  tlie  exception  of  the 
smaller  one,  may  be  used  to  the  best  advantage  in  con- 
nection with  a saw  table,  like  that  shown  in  Fig.  153. 
This  is  a plane  iron  table  having  a longitudinal  groove 
in  its  face  to  receive  the  g^liding  rib  of  the  carriage, 
shown  in  Fig.  154,  and  a transverse  groove  running 
half  way  across,  to  receive  a slitting  gauge,  as  sliown 
in  Fig.  153.  The  table  is  supported  by  a standard  or 
shank,  Avhich  fits  into  tiie  tool-rest  socket.  The  saw 


Fig.  152.  Making  a Cutter. 


mandrel  is  supported  between  the  centers  of  the  lathe, 
and  the  saw  projects  more  or  less  through  a slot  formed 
in  the  table.  The  gauge  serves  to  guide  the  work  to 
be  slotted,  and  other  kinds  of  work  may  be  placed 
on  or  against  the  carriage,  shown  in  Fig.  154. 

It  is  a very  simple  matter  to  arrange  guiding  pieces 
for  cutting  at  anv  angle,  and  the  saw  table  mav  be 
used  for  either  metal  or  wood.  The  saws  for  wood 
differ  from  those  used  for  metal;  the  latter  are  filed 
straight,  the  former  diagonally  or  fieaming.  Among 


IIOMI-]  1\1  KCIIAXICS  I 'OK*  AMA'I'KIJI.’S 


140 


11i(>  many  iis(>s  (o  wliicli  mclal  saws  may  he  ajtjilicd  w(‘ 
immlion  tlm  sliltinf>-  of  slmot  im-tals,  s])liti  iiij^  wii-os  ami 
rods,  slottiiio-  ami  j>rooviii,i^,  jiickiin;'  screws,  clc.  fi”-. 
155  shows  a lioldm*  for  rec<‘iviii<r  scr(‘ws  io  he  iiieke<l. 
It  is  used  in  coinieetion  with  the  saw  tahh*,  ami  is 
moved  over  the  saw  against  the  nanse. 

To  facilitate  tin*  removal  of  tlie  screws  tlie  holdei" 
may  lx*  s]>lit  loui>itndinally  and  liiiiijed  to<,u‘th(*r.  An- 
othei'  im'tlnxl  of  niekiny  sei*ews  is  illnsti-at(*d  hy  h5<r. 


150.  simple  lever,  fulcrumed  on  a bar  held  hy  the 
tool  post,  is  drilled  and  tapped  in  the  end  to  receive 
tin?  screw.  After  adjustini*’  the  tool  all  that  is  required 
is  to  insert  tlui  ser(*w  and  j^i'oss  down  the  handle  so 
as  to  hi-inj>-  tin*  sei-(*w  head  into  contact  with  the  saw. 

W'heix*  a la  tin*  is  provid<*d  with  an  en<>'ine  rest,  the 
cutter  sliowu  in  hi”-.  151,  monnt(*d  on  the  mandrel 
shown  in  h'ii*-.  150,  is  v<‘ry  ns<*fnl ; it  is  ns(*d  hy  clamp- 
ing Ihe  work  Io  lln*  slid(*  rest  and  moviiif'  it  under  the 
enller  hy  workinji  (In*  slide  rest  screw. 


HOME  MECHANICS  FOR  AMATEURS 


141 


To  make  a cutter  of  tliis  kind  is  more  difficult  than 
to  make  a saw,  and  to  do  it  readily  a milling  macliine 
would  l)e  recjuired.  It  may  be  done,  however,  on  a 
plain  foot  lathe,  by  employing  a V-shaped  cutt(*r  and 


using  a holder  (Fig.  152)  having  an  angular  groove 
for  receiving  the  cylinder  on  which  the  cutting  edges 
are  formed.  The  blank  can  be  spaced  with  sufficient  ac- 
curacy, by  means  of  a fine  pair  of  dividers,  and  after 
the  first  groove  is  cut  there  will  be  no  difficulty  in 
getting  the  rest  sufficiently  accurate,  as  a iiib  inserted 
in  the  side  of  the  guide  enters  the  first  groove  and  all 
of  the  others  in  succession  and  regulates  the  spacing. 

One  of  the  best  applications  of  this  tool  is  shown 
in  the  small  engraving.  In  this  case  a table  similar 
to  the  saw  table  before  described  is  supported  in  a 
vertical  position,  and  arranged  at  right  angles  with 


Fig.  155.  Holder  for  Screws. 


the  cutter  mandrel.  The  mandrel  is  of  the  same  diam- 
eter as  the  cutter,  and  serves  as  a guide  to  the  pattern 
which  carries  the  work  to  be  operated  upon.  The  prin- 
cipal use  of  this  contrivance  is  to  shape  the  edges  of 


(*ui‘V(m1  or  irr('i»iilar  iiK^tal  work.  Tin*  cast  ini;’  to  1)(‘ 
finisluMl  isfast(Mi(Ml — by  (‘(aiKMit  if  small,  and  by  (‘lam])S, 
if  lai\2:e — to  a i)ati(am  haviiif;'  exactly  the  shape  re^piircMl 
ill  the  fiiiisluHl  work. 


Fig.  156.  Nicking  Screws. 


By  movini»  the  ])atterii  in  coiita(‘t  with  the  talile  and 
the  mandrel,  while  the  latter  revolves,  the  ed^es  of 
the  Avork  will  be  shaped  and  finished  at  the  same  time. 
By  snbstitntino’  a conical  cutter  for  a cylindiacal  one, 
the  work  may  be  beveled;  by  nsini>’  both,  the  edge  may 
be  made  smooth  and  square,  Avhile  the  corner  is  bei^eled. 

The  tool  shown  in  Fig.  157  might  properly  be  called 
a barrel  saw.  It  is  made  by  drilling  in  the  end  of  a 


Fig.  157.  Barrel  Saw, 


st(‘(d  I'od  and  foianing  the  t(‘etli  with  a file.  To  avoid 
cracking  in  Bmijxalng  a small  hole  should  be  drilled 
throngh  1h(*  sid(‘  n(‘ar  tlu^  bottom  of  the  larger  hole. 
To  insure^  lln*^  fr(*("  working  of  the  tool  it  shonld  be 
tnriK'd  so  lhal  ils  cniling  (xlgc^  will  be  ratlun'  thi(‘ker 
Ilian  lh(‘  ])orlion  Ixdiind  it.  This  tool  shonld  be  made 
in  various  sizes. 


HOME  MECHAJ^ICS  FOR  AMATEURS 


143 


EASILY  MADE  SLIDE  REST 

While  the  most  of  the  work  to  be  done  on  the  foot 
lathe  may  be  accomplished  as  expeditiously  and  quite 
as  well  without  a slide  rest  as  with  it,  yet  there  are 
some  operations  that  are  greatly  facilitated  b}^  means 
of  this  tool.  Boring,  for  example — a very  difficult  thing 
to  do  with  hand  tools — may  be  done  quickly  and  ac- 
curately by  using  a slide  rest.  In  gear  cutting — de- 
scribed in  another  part  of  this  section — a slide  rest  is 
essential. 


Pig.  158.  The  Complete  Slide  Rest. 


In  the  case  of  this  tool,  as  well  as  others  previously 
described,  the  purchase  of  a well-made  article  is  recom- 
mended. A"et,  if  one  has  time  and  feels  so  inclined,  he 
mav  make  a reallv  efficient  slide  rest  with  no  other 
tools  than  his  lathe  and  ordinary  turning  tools.  Figs. 
158  to  160  inclusive  represent  a slide  rest  that  may  be 
made  in  this  way.  Fig.  158  being  a perspective  view, 
and  Figs.  159  and  160  respectively  longitudinal  and 
transverse  sections  of  the  tool  carriage. 


144 


MKCILANICS  KOU  A.MATKUKS 


Tlie  T-slia])(Ml  (‘astiiii;',  A,  lias  a loiii^il udinal  slot, 
which  is  ma(l(‘  T-shaj)C(l  in  (‘ross  scMdion  to  i'(‘(*(‘iv(‘  1h(‘ 
head  of  the  bolt  that  ('oiitiiu^s  it  in  ])osiiioii  upon  the 
plate  fitted  to  the  lathe  bed.  Tln^  veidieal  (^ai's  at  oji- 
posite  ends  of  the  casting’  i\n)  bored  to  r(M‘(‘i\(‘  tin*  (aids 
of  the  rods,  11,  npoii  which  the  tool  carriai;(^,  C,  slides. 

The  first  operation  in  niakinj;*  the  slide  r(‘st  is  to 
make  one  side  of  the  casting,  C,  perfectly  plane.  It  is 


Fig.  159.  Longitudinal  Section  of  Slide  Rest. 


Pig.  160.  Transverse  Section  of  Slide  Rest. 

tlnai  chnck(Hl  in  the  lathe  with  the  plane  side  next 
th(‘  fac(‘  plat(\  Three  holes  are  bored  through  it,  two 
for  th(^  1‘ods,  r>,  and  a smaller  one  for  the  screw,  (i. 
It  is  llnai  (*hnck(‘d  on  an  angle  ])late,  so  that  the  holes 
f(a‘  tli(‘  rods,  I>,  ar(‘  cMpially  distant  from  tlu^  (‘enter  liiui 
of  lh(i  lath(%  and  IIk*  hol(‘  for  ih(‘  rod  1>,  is  bori^d  very 
(‘arcdiilly  lo  insure*  IIk*  parall(‘lisni  of  its  sid(\s.  Tin* 
casling.  A,  is  now  pla(‘(*d  upon  a plane  surface,  and  the 


HOME  MECHANICS  FOR  AMATEURS 


145 


casting,  C,  is  clamped  to  the  ear  at  one  of  its  ends,  and 
adjusted  so  that  a line  drawn  through  the  center  of 
the  holes  is  exactly  parallel  with  the  bottom  of  the 
casting.  The  casting,  C,  is  used  in  this  manner  as  a 
template  for  drilling  both  of  the  ears  for  the  reception 
of  the  rods  B.  It  will  be  necessary  to  exercise  great 
care  in  drilling  these  holes,  as  it  is  of  vital  importance 
to  have  the  rods,  B,  perfectly  parallel. 

The  casting,  C,  may  now  be  tapped  to  receive  the 
screw,  G,  and  the  tool-carrjdng  bar,  D,  may  be  fitted 
to  its  place,  and  turned  down  and  threaded  to  receive 
the  internallv  threaded  boss  of  the  wheel,  E.  This 
boss  is  fitted  to  the  base  of  the  casting,  C,  and  is  grooved 
circumferentially  to  receive  a split  ring,  F,  the  latter 
being  drilled  to  receive  the  ends  of  three  screws  that 
project  through  the  casting  into  it  and  prevent  the 
boss  of  the  wheel,  E,  from  moving  lengthwise  of  the 
hole,  while  the  arrangement  permits  of  the  free  rotation 
of  the  wheel.  The  bar,  I),  has  a head  which  is  drilled 
vertically  to  receive  the  tool  post,  and  is  provided 
with  a heavy  feather  at  the  top,  which  is  received  by 
the  slot  formed  by  sawing  into  the  upper  portion  of  the 
casting,  C.  To  render  the  bearing  of  the  bar,  D,  sonie- 
Avhat  adjustable,  two  screws  pass  through  the  casting 
aboA’e  the  feather.  The  tool  post  is  of  the  usual  de- 
scription, having  a loose  collar  above  the  head  of  the 
bar,  I),  and  a nut  below  it.  The  mortise  for  receiving 
the  tool  extends  a little  below  the  loose  collar,  so  that 
Avhen  the  tool  is  clamped  the  post  and  ring  Avill  also 
be  clamped.  A slot  is  cut  through  the  bottom  of  the 
casting,  C,  into  each  of  the  guide  rod  holes,  to  permit 
of  adjustment  in  case  of  Avear  by  means  of  the  screws 
Avhich  pass  transversely  through  the  slot.  The  ends  of 


14G 


WOMh]  iMKCIIANICS  ¥i)\l  A^\\TK¥\IH 


llie  rods,  1>,  are  fastcauMl  hy  a similar  <1(‘\  i(‘(‘.  Thy  s(‘T'(nv, 
(),  is  ])reveiit(‘d  fi'om  (aid  motion  l)y  a slioidd(‘r  on  tlie 
outside  of  tlie  (air  at  tlie  (-rank  (md,  and  a (‘ollai*  on 
tlie  insidca  Tlie  rods,  1>  and  I),  may  lie  mad(^  of  stead 
or  of  cold  rolled  iron;  the  latter  Avill  h(‘  tian^  (‘noni»li 
without  tnrnini*'.  The  eastini»’  may  Ix^  (dth(‘i‘  of  brass 
or  iron;  a i>‘ood  (]iiality  of  iron  will  jaadiajis  ])rov(‘  the 
most  satisfactory.  The  slots  may  be  cut  with  the 


Fig.  161.  Boring  Attachment. 


saws  descrilxal  in  a former  article.  The  tools  to  be 
ns(xl  with  the  slide  rest  have  also  been  previously 
(h'scrilxxl. 


In  kit;.  Kil  is  r(‘])r(‘S(mt(al  a borini^*  d(Ai(‘e  whi(di  will 
lx*  r(*adily  nnd(*rstood  without  S]x*(dal  d(*S(*rii)t ion.  The 
castinit,  A,  is  titt(‘d  to  tlui  tool  r(*st  so(‘k(*t  and  ])i*ovide(l 
Avith  a sliding  bai*,  l>,  \\dii(di  is  like*  tin*  bai',  1),  in  the 
slide*  r(*st  above*  ele*scidbe*el,  (‘xe‘(*pt  in<»-  that  its  ba(*k  end 


HOME  MECHANICS  FOE  AMATEUES  147 


is  rounded  and  provided  with  a pin  which  slides  in  the 
slotted  arm  attached  to  tlie  tail  spindle  of  the  lathe  by 
which  it  is  moved,  instead  of  havhi<>’  a moving  device  of 
its  own.  With  this  tool,  boring  and  some  kinds  of  out- 
side turning  may  he  done.  It  is  less  expensive  than 
the  slide  rest  and  answers  a good  purpose.  It  is  prob- 
able that  in  making  both  these  tools  the  services  of  a 
mechanic  provided  with  a planer  or  shaper  will  be  re- 
quired. 


INDEX  PLATES  FOH  GEAK  CUTTING 

There  aie  manv  amateurs  who  would  make  their 
own  gear  wheels  were  it  not  for  the  expense  of  pur- 
chasing or  the  trouble  of  dividing  and  drilling  the 
index  plate,  which  is  the  principal  item  in  the  ap- 
paratus required  in  cutting  small  gears. 

Of  course  an  index  plate  may  be  purchased,  but  the 
money  thus  laid  out  would  go  a long  way  toward  pay- 
ing for  cutting  all  the  gears  that  Avould  ever  be  re- 
quired l\y  most  amat(Mirs. 

It  is  admitted  that  it  is  difficult  to  obtain  absolute 
accuracy  l)y  ordinary  methods,  but  the  plans  here  sug- 
gested Avill  probably  give  as  uearh^  perfect  results  as 
can  be  obtained  without  copjdng  another  index  plate 
or  using  a dividing  engine. 

The  index  plate,  before  being  divided,  should  be 
■ nicely  turned  and  fitted  to  the  place  it  will  occupy  on 
the  lathe.  Tliis  will  generally  be  on  the  larger  side  of 
the  cone  pulley. 

Two  methods  of  graduating  an  index  plate  are  il- 
lustrated by  the  accompanying  engravings.  One  con- 


148 


iwm:  ]\iKciiAxi(^s  foii  amai^ki  i?s 


sists  ill  l()(‘atiii|L>  tli(‘  liol(‘s  by  iisiiijL>*  |>a])(*i*  s(*al(‘s  wlncli 
ai'(‘  ])riiit(‘(l  from  (aii»iii(^  dividiMl  ])lat(‘S,  and  ari^, 
forc^,  Aery  nearly  aeimrati*.  Tin*  otlna'  (‘(insists  in  divid- 
ini»  tlie  plate  by  aid  of  a lari>(‘  ])a])(n'  disk  gradual (*(1  by 
hand. 

Vov  the  most  of  ])nr])()S(^s  four  rows  of  liol(*s  Avill 
answei'.  The  Ix^st  nnndxa'  of  h()l(‘S  foi'  tin^  (lirf(‘r(mt 
I'ows  is  as  follows:  240,  200,  144,  122.  240  (‘an  b(‘ 

dividiMl  as  follows:  120,  00,  48,  40,  20,  20,  15,  12,  0. 
AVith  200  divisions:  100,  50,  40,  25,  20,  10  and  5 may 
be  made.  144  divides  into  72,  48,  2(i,  24,  18,  10,  12, 

I) ,  8,  0.  122  into  00,  44,  22,  22,  1 1. 

The  best  method  of  dividing’  an  imhvx  ])late  of  whi(‘h 
the  Avriter  has  any  knoAvl(Hl<»e,  asid(^  from  dn])lieatinf>f 
another,  or  nsinj>*  a dividing*  enjL^im^,  is  shoAvn  on  the 
next  pai>e.  A Avooden  block.  A,  is  attached  to  the  fa(‘e 
])late  of  the  lathe  by  means  of  screAvs,  and  turned  doAvn 
truly  on  the  face  and  n])on  the  ed<;e.  A portion  of  the 
edji^e  is  turned  to  a suitable  diameter  for  receivinjj^  a 
(‘ertain  len!L>th  of  paper  scale,  C.  The  other  portion  of 
the  is  pressed  by  a brake  shoe,  F,  Avliich  is  kept 

II] )  by  a s(‘rew  in  the  standard,  1).  An  index,  E,  is 
slotted  and  secnixxl  to  the  top  of  the  standard,  D,  liy 
a s(‘rew.  To  the  fa(‘e  of  the  bl()(‘k.  A,  is  secured  the 
imh^x  ])late,  11,  and  in  front  of  the  plate  there  is  a drill 
snpjiort  whi(‘h  tak(‘S  the  ])lace  of  the  ordinary  tool  ix^st. 
Tho  drill  is  (‘a])abl(‘  of  longitudinal  as  Avell  as  rotary 
mol  ion  in  ils  sn])p()rt;  it  is  driv(m  l)y  a Ixdt  from  the 
(lriv(^  \\4i(*(d  of  IIk^  lalln*,  and  is  inisluxl  forAvard  a lim- 
il(xl  (lislan(‘(‘  by  lli(‘  handb^  swiv(‘l(‘(l  to  tlu^  end  of  the 
drill  S])in(ll(*.  Tlui  siz(‘  of  lh(‘  di'ill  Avill  Ix^  i»()V(n‘n(xl 
allo.!4(4  li(n‘  by  I In*  siz(‘  of  IIkj  plal(S  bnl  in  any  (‘ase 
it  should  b(‘  as  lari;(^  as  |x)ssibl(‘,  always  b(‘aring‘  in 


HOME  MECHANICS  EOK  AMATEUES 


14!? 


mind  tliat  the  space  between  the  holes  should  he  of  sub 
ticient  width  to  insure  the  recpiired  strength. 

That  portion  of  the  wooden  block,  A,  which  receives 
the  paper  scale,  C,  is  carefnllj  turned  so  as  to  permit 
the  ends  of  the  scale  to  abut ; the  scale  being  very  care- 
fully cut  so  that  its  ends  will  join  accurately  and  render 


Fig.  162.  Method  of  Graduating  Index  Plates. 


the  graduations  of  the  scale  tiniform  throughout.  The 
scale  is  best  attached  to  the  block  by  means  of  paper 
tacks  or  small  screws.  For  the  greatest  number  of 
graduations  given  above,  a two  foot  paper  scale,  or 
two  pieces  of  shorter  scales,  will  be  required.  The 
inches  should  be  divided  into  tenths.  The  block  should 
be  7.04  inches  in  diameter  where  it  is  surrounded  by 


150 


IIOAIK  MI^XUIANICS  ]’OK  AAIA'l'KUIlS 


llie  scale.  Tlic  diaiiK'lcr  of  lliat  ])avl  ciimaiLied  l»y  I lie 
hi'ake  slioc  is  n(»t  liiiiilcd  io  any  pari ictilar  siz(“. 

It  is  obvious  tliat  for  drilliu*^  240  liol<‘s  cvci-y  mark 
oil  tile  seal(‘  must  be  brou,i>lit  o])])osit(!  tin*  imb’x,  J'], 
and  stopjied  by  means  of  llie  brake,  k',  while  a bob*  is 
drilled.  After  drillini*’  this  row  of  liob*s,  tin*  row  eoii- 
taininj;  144  boles  sbould  be  drilb“d,  b*avinf>’  a siiaee 
between  it  and  tlie  240  row  foi*  tlie  200  row.  for  Ibe 
144  row  the  ojx'ration  is  the  same  as  that  alri-ady 
described,  except  that  a scale  divided  into  twi'lftbs  is 
used,  and  alternate  graduations  only  are  noticed.  The 
intermediate  oiii's  should  be  crossed  out,  so  that  the 
scale  will  really  be  a scale  of  inches  divided  into  sixths. 
For  the  132  row  the  block  is  turned  down  to  7 inches 
diameter,  and  the  scale  last  used  is  shortened  to  22 
inches  and  again  applied  to  the  block  and  used  as 
before. 

After  completing  these  rows  of  holes  the  drill  is 
moved  to  the  space  between  the  first  and  second  rows, 
the  block  is  turned  down  to  6.36  inches,  and  20  inches 
of  the  paper  scale  first  used  (inches  divided  into 
tenths)  is  employed.  Every  graduation  on  the  paper 
scale  is  used  in  this  case  as  in  the  first  instance.  This 
gives  200  divisions. 

Th(i  pap(*r  scales  recommended  for  this  purpose  are 
I hose  used  by  engineers  and  draughtsmen.  They  may 
b(!  obtaiiK'd  for  a f(*w  cents  from  any  dealer  in  mathe- 
matical instruments. 

In  I'ig.  163  lh<*  larg(‘r  circle  represents  a disk  of 
payx'r  which  is  carefully  divid(*d  into  large  spaces  by 
means  of  ordinary  dividei*s,  and  the  large  spaces  are 
subdivided  in  llie  sanu*  way. 

In  tlie  c<‘nl<‘r  of  (be  |ia])er  disk  is  i)lac(“d  the  ])late  to 


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151 


be  divided,  aud  from  the  center  of  the  plate  rises  a 
stud,  to  which  is  accurately  fitted  the  sleeve  attached 
to  the  eud  of  the  radius  bar.  The  radius  bar  extends 
beyond  the  outer  circle  on  the  paper  disk,  aud  carries 
au  adjustable  sleeve,  to  which  is  accurately  fitted  a 


drill  which  may  be  rotated  by  means  of  a small  drill 
stock.  The  sleeve  that  forms  the  bearing  of  the  ra<lius 
bar  is  shown  in  detail  in  the  lower  left  hand  corner  of 
the  engraving,  and  the  sleeve  that  receives  the  drill  is 
shown  in  the  opposite  corner. 

While  drilling,  the  radius  bar  is  held  in  place  by  a 


152  IIOMK.  MKCTTANICS  FOU  AMATFUKS 


Avciii>lil  or  by  inoaiis  of  a claiii]).  Af((‘r  (Irilliiiju:  (‘acli  liolo 
tli(‘  l)ar  is  iii()V(m1  forward  oik^  s])a('(*  and  s(M*nr(Ml  l)y  lli(‘ 
Aveii>lit  or  (dani]).  A\dH‘n  om^  i*ow  of  liol(‘S  is  (‘oin])l(^t(Ml, 
tlie  sloovo  wlii(di  iiiiides  ilie  drill  is  niov(Hl  toward  tlio 
renter  of  tlie  disk^  and  ilie  o])(n'ation  of  dialling  is  ('ur- 
ried  on  as  before.  this  nudliod  wliate^a^r  errors  may 
exist  in  the  <>i'adnations  on  the  ])ai)er  disk  aia^  i>r(‘atly 
redneed  in  the  ind(‘x  ])lat(^,  and  llie  ])lat(^  ])rodn(‘(Hl  will 
be  a(‘enrate  enon<>li  for  most  pnrposc^s  if  tlu^  work  on 
the  ])ap(a‘  disk  has  been  earc^fnlly  don(‘.  Tln^  smalh^st 
plate  should  be  at  least  three-sixtcHmihs  of  an  inch 
thiekj  and  the  holes  shonld  not  Ix^  dialled  (piite  throni»h. 
Either  iron  or  lirass  may  lie  used  for  the  disk.  The  lat- 
ter works  the  easiest  and  will  answer  eA^ery  purpose. 


GEAE  CUTTING  ArrAEATUS 

The  index  plate.  A,  is  attached  to  the  larger  of  the 
])nlleys  on  the  mandrel  of  the  lathe  l)y  means  of  three 
or  four  screAA  s,  and  the  stop,  C,  provided  Avitli  a point 
Avell  fitted  to  the  holes  in  the  plate,  is  held  in  position 
on  the  bed  plate,  B,  by  a screAV  X3assing  throngh  a slot  in 
the  foot  into  the  bed  piece.  The  stop,  C,  is  capable  of 
siiringing  sufficiently  to  admit  of  aa  ithdraAA  ing  the  pin 
fi'om  the  hole  in  the  x>hite,  and  it  is  strong  enough  to 
hold  the  ])late  Avithont  vibration.  Tavo  standards,  G, 
moiint(xl  on  the  ])late,  B,  snjiport  pulleys  oxev  Avhich 
tin*  diaving  b(dt  runs.  The  gear  (aitter  head  consists  of 
a casling,  1),  filt(‘d  to  the  tool  ])ost  of  the  slide  rest, 
and  th(^  mandixd,  E,  i)rovid(xl  with  a ])nlley  and 
nionnj(xl  on  (‘arcdully  litt(‘d  c(mt(‘rs  in  ihe  (-asting.  The 
casi  ing,  I ),  has  ni>on  ojiposih^  sid(‘S,  m^ar  tln^  upper  end, 
(*ai‘S  (as  shown  in  fdg.  Ibr))  for  rcHaaving  the  jinlleys, 


HOME  MECHANICS  FOR  AMATEURS 


153 


Fig.  164.  Apparatus  for  Gear  Cutting. 


154: 


IIOMK  i^II^XJIIAXKJS  VOU  AMAIManW 


f/  />,  wliicli  i;ni(l(^  ihv  driviiii;  l)(*ll,  so  Dial  IIk^ 
may  1)(^  rcanovcMl  aci'oss  lli(‘  fa(*(^  of  I Ik*  \v1k*(*I  ))(*iiii»  rui 
wiflioTit  (‘liani»iiij»  IIk*  l(*iision  of  11k*  ))(*lt.  TIk*  (*x- 
ti*(*me  end  of  tlie  loop  formed  l)y  IIk*  l)(*lt  is  sii])port(*d 


Fig.  165.  Detail  of  Gear  Cutter. 


l)y  the  pulley^  IT,  mounted  on  a standard  rising  from 
the  lathe  bed.  The  standard  may  be  placed  far  enough 
from  the  slide  rest  to  admit  of  putting  the  tail  stock 
l)etween  it  and  the  slide  rest  in  case  it  should  be  neces- 
sai'y  to  use  the  tail  stoi'k  for  supporting  the  work. 


Detail  of  Pulleys. 


Cutters. 


HOME  MECHANICS  FOR  AMATEURS 


155 


The  mandrel,  E,  is  provided  with  a collar  and  a nnt 
for  clamping  the  cutter,  E.  It  will  be  noticed  that  the 
cntter  comes  exactly  opposite  the  line  of  the  lathe  cen- 
ters, and  that  it  occnpies  abont  the  same  position,  in 
relation  to  the  tool  post,  that  the  point  of  an  ordinai\y 
turning  tool  does.  The  cntter,  E,  is  shown  in  Eig.  KtB, 
enlarged.  The  upper  view  represents  the  side,  the 
lower  view  the  edge  of  the  cntter.  It  has  but  a single 
tooth  and  is  adapted  to  brass  and  similar  alloys  only. 
It  maj^  be  sharpened  by  grinding.  When  iron  or  steel 
is  to  be  cut  the  cutter  should  have  several  cutting  edges, 
and  the  mandrel,  FI,  should  have  a larger  pulley,  as 
more  power  will  be  required  and  tbe  speed  must  be 
slower.  By  setting  the  slide  rest  at  an  angle  bevel 
gears  may  be  cut. 


HINTS  ON  :\IODEL  MAKING 

It  is  a simple  matter  for  au  experienced  instrument 
maker  or  macbinist  to  ]U'oduce  a tine  model  with  turned 
shafts,  cut  gearing,  true  pulleys,  and  smooth  working 
cams,  but  it  is  quite  another  thing  for  an  inventor, 
Avithout  tools  or  materials,  to  embody  his  ideas  in  a 
Avorking  model  even  though  he  may  have  a mechanical 
taste. 

It  is  fair  to  suppose  that  cA'ery  mechanical  inA’entor 
in  these  days  of  cheap  machinery  possesses  some  sort 
of  a lathe,  as  these  iudisi>ensable  machines  are  noAv 
made  for  prices  Avithin  the  reach  of  almost  aiiA-  one. 

It  is  quite  evident,  from  an  inspection  of  the  models 
of  the  Patent  Office,  that  most  inventors  who  under- 
take to  make  their  oavu  models  expend  a great  deal  of 
labor  Avithout  corresponding  results.  In  the  matter  of 


150 


irOMF.  MFCniAXK^S  Foil  IIS 


<»(‘ariiim,  for  iiisiaii('(‘j  oii(‘  will  wliitlF*  liis  w1h*(‘1s  in 
Avood,  anollKn^  will  boi'roAv  liis  i»(^ai'iii!L>  from  soim^  (1(‘- 
fiincl  (‘lo(‘k,  Avliile  sOll  aiiollior  will  ])iir('Iias(^  I'c^ady- 
made  avIkhOs  from  om*  of  oni'  w(dl  known  fiimis  makinij^ 
a bnsim^ss  of  fnrnisbin<>  ])arts  of  imxbds. 

Of  the  tlir(‘o  nu^tliods  of  obtaining’  tbo  ^(^aia‘ni»:  tlm 
latter  is  undoubtedly  iln^  best,  as  all  that  is  nec-essary 
to  l)e  done,  in  (‘ase  of  tlie  (-ast  <»(^ar  avIkmOs,  is  to  bore 
them  and  tile  np  tbe  t(Hdli,  and  as  tin*  (*nt  i»ear  Avliecds 


Pig.  167.  Friction  Gearing 


are  iG^enerally  bored,  the  shaft  may  be  fitted  Avithont 
fnidlna'  Avork  on  tbe  Avheids.  It  is,  lioAvever,  seldom 
absolntidy  mxx^ssary  to  use  toothed  j[]^earin«;,  as  rotary 
mol  ion  may  b(^  ix^adily  transferrcxl  by  suitable  fri(‘tioii 
aa'Ikx'Is  ot*  by  <»i'oov(‘d  or  s])roeket  Avheels  and  a round 
b(‘lt. 

1()T  shows  a form  of  fiacdion  j[*’earin<ij  Avhich  is 
both  sim])le  and  (idVel i v(*.  Th(‘  lai\i»(‘r  Avheel  is  simply 
a disk  of  slnxd  brass  having*  round(Ml  (xl<»("S,  and  boss 


HOME  MECHANICS  EOK  AMATEUliS 


157 


spun  or  soldered  on,  and  a smaller  wheel  consists  of  two 
swaged  disks  of  steel  having  their  convex  faces  sepa- 
rated by  a metal  washer  a little  thinner  than  the  large 
wheel.  These  three  members  are  secured  to  a common 
boss  by  spinning  the  end  of  the  boss  partly  over  one  of 
the  disks,  as  shown  in  the  sectional  view.  No.  2.  This 
form  of  friction  gearing  is  noiseless  and  runs  strong 
enough  for  the  requirements  of  almost  any  model. 

Figs.  168  and  169  show  a form  of  sprocket  wheel 


Fig.  168. 

Sprocket  Wheels. 


Fio.  169. 


Avliich  is  readily  made  and  is  almost  as  positive  in  its 
action  as  gearing.  In  this  case  the  two  wheels  are 
alike ; they  consist  of  disks  of  sheet  metal  nicked  to  a 
uniform  depth  from  the  edge,  and  the  arms  thus  formed 
are  bent  alternately  in  opposite  directions,  forming  a 
groove  for  receiving  the  round  belt  used  in  transferring 
motion  from  one  wheel  to  the  other.  It  is  evident  that 
a belt  cannot  slip  on  a wheel  of  this  construction. 

Fig.  170  shows  a form  of  friction  geainng  for  trans- 
ferring motion  at  right  angles,  and  for  imparting  a 
variable  speed  to  a shaft  from  another  shaft  running  at 


158 


JlOiMi^]  MJailA.NICS  Fi)\l  .UWTKIU^ 


a luiiforin  rat(^  Tlie  lar!L»(*  wIkm^I  in  lliis  inslanc(‘  is 
luerc^ly  a ])lan(^  disk  of  in(*tal  inouidfMl  in  ili(*  inaim(*i‘ 
already  described.  Tlu^  sinall(‘r  w1h‘(*1  is  a i»i'<)ov(m1 
metal  ])ulley  snrronmbMl  by  an  (‘lasti(*  rnblxn'  riniL». 
Tin’s  is  ])ress(Ml  with  more  or  b^ss  for(‘(^  ai^ainst  tln^  im*- 
talli(‘  disk,  and  its  S])eed  may  b(^  vaincMl  by  moving  it 
towaiul  or  away  from  the  axis  of  tln^  <lisk. 

As  to  the  matter  of  irref»nlar  motion  nsnally  im- 
])arted  by  cams,  it  is  difficult  to  make  a cam  in  tlie  ordi- 


Fig.  170.  Transferring  Motion  at  Right  Angles. 

nary  Avay  with  the  millino^  machine,  and  there  appears 
no  verw  simple  way  of  cutting  them  from  solid  castings. 
There  is,  however,  a simple  way  of  building  them  up 
from  readily  obtained  materials. 

hbg.  171  shows  a cam  consisting  of  a cylinder  of  brass 
or  a short  S(H*tion  of  brass  tubing  provided  with  two 
In^ads  and  monnt(‘d  on  a shaft.  The  (‘am  groove  is  laid 
out  on  this  surface*,  and  1 wo  ])arallel  ])ieces  of  sepiare 
brass  wir(‘  are*  solde*i‘e*d  fo  the*  sniTae‘(*  of  the  e'ylinder, 
or  fasle*ne*el  by  nie*ans  of  se‘re*ws.  The*y  are  ])lae‘e*el  uni- 
formly dislant  llii'onghoni  I he*  entire  e‘irenmf(*rene‘(*  of 
tliei  cylinele*r. 


HOME  MECHANICS  FOR  AMATEURS 


159 


Fig-.  172  shows  a cam  built  up  in  the  same  way  on  the 
face  of  a disk. 

As  to  shafts,  the  model  maker  may  save  himself  much 
labor  and  expense  by  using  Stul)bs’  steel  for  small 
shafts,  and  cold  rolled  iron  for  larger  ones.  Either 
the  steel  or  iron  may  be  bought  in  one  and  three  foot 
lengths. 

Almost  anything  in  the  wa_y  of  parts  of  models  may 
be  purchased  ready  for  use,  so  that  all  the  inventor  need 
do  is  to  combine  them  and  mount  them  on  a suitable 


Fig.  171.  Drum  Cam.  Fig.  172.  Disk  Cam. 


frame;  but  even  so  simple  a matter  as  a wooden  frame 
for  a model  sometime  proves  troublesome. 

The  small  tenons  and  mortises  are  difficult  to  make, 
and  the  frame  to  be  strong  enough  to  bear  handling 
must  be  made  so  heav}'  as  to  be  entirely  out  of  propor- 
tion. A simple  and  easy  method  of  securing  the  joints 
of  small  frames  is  to  clamp  the  parts  in  the  position 
they  are  to  occupy  in  relation  to  each  other,  and  then 
drill,  with  a sharp  twist  drill,  two  holes  through  one 
piece  from  side  to  side  and  into  the  end  of  the  abutting 
piece,  then  inserting  two  hard  wood  pins,  having  previ- 
ously coated  them  with  glue.  This  makes  a joint  far 
stronger  than  the  mortise  and  tenon,  and  it  is  very 
quickly  done. 


IGO 


ilOMK  MI^XUIANK^S  Vi)\l  AMA^M^RS 


METAL  SIMXMNX; 

Tlie  opcn-ation  of  s])iiniiii!L»  nuMals,  alllioii^li  (‘X(‘(‘(‘(l- 
simple  and  (‘apal)le  of  Ixaiii*  j)ra(‘l i(‘(Ml  to  advan- 
ta<»’e  ill  almost  every  slio]),  and  also  by  (li(‘  amatiair  m(‘- 
clianie  njion  tln^  foot  latlu^,  is  not  <>’(‘n(M'all y inuba'stood. 
One  reason  for  this  is  that  the  artisans  who  follow  this 


Fig.  173.  Metal  Spinning. 


branch  of  m(*chani(‘S  as  a.  business  nsnally  condind  it 
niKha*  locki^l  doors,  and  it  is  \yith  considerable  diffi- 
culty that  theamat(Mir  in  sear(*h  of  information  on  this 
and  kindri'd  subj(M‘ls  (‘an  oblain  (uitraiu'c^  to  one  of 
lli(^s(^  ('slablishmcmts.  ''PIk*  r(‘ason  of  ihis  S(‘cr(M‘y  is 
plain  (mough,  as  (he  ^‘kink’’  or*  ^‘wrinkh*/^  or,  in  plain 


HOME  MECHANICS  FOE  AMATEUES  Id 


English,  the  knowledge  required  to  do  the  mechanical 
part  of  spinning  is  so  slight  that  secrecy  is  the  only 
protection. 

The  tools  required  are  few.  They  consist  of  a lathe ; 
a form  or  mould  on  which  to  shape  the  article;  a tool 
rest  with  a series  of  holes  for  receiving  a pin  to  keep  the 


Fig.  174. 


Fig.  175.  Spinning  Tools. 


tool  from  slipping,  and  a few  spinning  tools  or  burnish- 
ers of  different  sizes  and  shapes. 

The  lathe  the  amateur  is  supposed  to  possess;  the 
tool  rest  he  may  easily  make ; and  the  only  other  addi- 
tion to  the  lathe  will  be  a back  center  of  the  form  shown 
in  Fig.  174.  This  form  of  center  answers  as  a step  to 
the  work  holder,  and  will  bear  considerable  pressure 
without  undue  friction. 

The  tools  required  are  shown  in  Fig.  175.  These  are 


H;2  ilOMK  MKClIAN’ ICS  KOI!  AMA'I’KKKS 


sim])ly  liard  sic'cl  hiiniislicrs  of  I lie  form  sliowii,  jiiid 
Viiryiiifi'  in  sizo  with  the  siz(*  and  kind  of  work  to  h<* 
<loii(*.  The  siz(‘  yiven  in  the  en^i-ivini;  is  about  ri^ht  foi- 
amateur  work  on  a foot  lathe.  No.  1 shows  i!i  two 


Fig.  176.  Fig.  177. 

The  Forms  in  the  Lathe. 


viow s a ))all  tool.  No.  2 sliows  hath  sido  and  edge  views 
of  a (:iirv(*d  iooL  No.  shows  a i)laiii  i-onnd  biiriiislier. 
In  soiiKi  inslnii(*(‘s  ii-  may  l)(‘  n(‘(*(‘ssary  fo  make  tools  of 
diHViMMil  foniis.  ’ TIk*  o|)(‘i‘alor  will  Ix^  gnidcxl  in  tlie 
sel(*clion  of  his  (ools  by  (h(‘  paidienlar  work  in  liand^ 


HOME  MECHANICS  FOR  AMATEURS  163 


and  practice  will  bring  new  suggestions  as  to  tlie  tools 
and  the  manner  of  using  them. 

The  materials  generally  used  in  spinning  are  brass, 
copper,  zinc,  hritannia  metal  and  lead.  All  of  these 
may  be  worked  on  the  foot  lathe,  but  perhaps  the  ama- 


Fig.  179.  Fig.  180. 

The  Movement  of  the  Tool. 

teur  will  dorive  the  most  satisfaction  at  first  by  using 
hritannia  metal,  as  it  works  easily  and  does  not  require 
annealing.  Articles  in  this  metal  also  present  a hand- 
some appearance  when  done,  whether  simply  polished 


Fig.  181.  Spinning  without  a Form.  Fig.  182.  Spinning  a Ring. 

or  plated.  Zinc  must  be  spun  quite  hot.  Articles  of 
brass,  if  of  considerable  depth,  must  be  annealed  when 
partly  done. 


Tlie  form  on  wlii(‘li  tlu^  im^lal  is  s])uii  ma,y  lx* 
liard  or  soft  wood  oi'  nudal.  A !L»()od  (*los(^  i»i'ain(‘d  ])in(‘ 
answers  as  av(‘11  as  anvtliinin^  for  most  ])iir|)os(‘Sj  and  is 
vcaw  rc^adily  tiirmnl  to  tlie  recinired  form.  It  mav 
attached  to  tlu^  fa(*(‘  ])lat(%  1>,  and  tlu^  disk  to  b(‘  s])iin 
may  he  held  against  it  at  first  hv  a liard  wood  oi‘  medal 
])i(‘co,  (',  ;is  sliowii  ill  Fiji's.  17<!  and  ITT,  wliicli  is  forced 
aiiainst  tlie  disk  by  tlie  tail  center.  After  the  spinning' 
is  a little  advanced,  a cipi-sliajied  bolder  is  ajijilied,  as 
shown  ill  dotted  lines  in  l''ig'.  ITT.  Sonietinies  the 


Fig.  183.  Concave  Reflector. 


Fig.  184.  Cup. 


holder  is  secured  by  a holt  that  runs  through  both  it 
and  the  form  or  mould,  as  shown  at  D,  Fig.  1T8.  In 
some  cases  a little  rosin  is  applied  to  the  form  to  in- 
crease the  friction,  hut  this  is  rarely  necessary.  The 
motion  of  the  lathe  should  he  quite  rapid,  and  the  disk 
should  receive  a coating  of  grease  (lard  or  heavy  oil) 
before  applying  the  hnrnisher.  A very  strong  solution 
of  soap  may  h(‘  used  instead  of  oil.  The  position  of  the 
workman  and  I he  manner  of  holding  the  tool  may  be 
seen  in  k'ig.  IT^k  It  will  be  noticed  that  the  iiin  in  the 
tool  res!  serves  as  a fnlcrnm  for  the  tool,  which  must 
be  brongiil  will)  considei'able  pressure  against  the  siir- 


HOME  MECHANICS  FOR  AMATEURS 


165 


face  of  the  disk.  This  pin  is  moved  forward  from  time 
to  time  as  the  work  advances.  The  movement  of  the 
tool  may  be  seen  in  Figs.  179  and  180.  The  shape  taken 
by  the  metal  in  front  of  the  tool  will  also  be  seen.  In 
swinging  the  tool  toward  the  form  it  is  moved  in  the 


direction  of  the  arrow  as  shown  in  Fig.  179,  and  it  is 
carried  back  as  shown  in  Fig.  180.  This  last  operation 
is  very  essential  to  the  proper  fitting  of  the  mould,  and 
it  also  thickens  the  metal.  Too  much  should  not  be 
attempted  at  a time.  A succession  of  quick  movemeuts, 
as  indicated  in  Figs.  179  and  180,  under  a moderate 
pressure  is  much  better  than  to  do  a great  deal  of  exe- 
cution at  a single  stroke.  Should  the  metal  tend  to 


160 


iroMK  MK(:ilANI(;S  foi;  AMAI’FUKS 


vibrato  or  biickl<‘,  a |>i<>c(*  of  wood  may  !)(>  a])])li<“<l  to  tlie 
back  witli  tlic  loft  liaad,  as  sliowii  in  1-^^.  178. 

Tlie  niotbod  of  spiiuiiiif'  a cii])  or  pol  witliont  a form 
is  illnstratod  in  Fi,<«-.  181.  lion*  tlio  im-lal  is  sni)]»orlo<l 
bj  a plain  cylindrical  mandrel,  and  is  tirst  spnji  into 


tlio  form  indicatod  by  the  dotted  lines,  and  then  bring- 
ing tlio  l»nrnisb(‘r  on  the  return  stroke  only  to  the 
slionidor  winch  forms  tin*  larger  ])art  of  the  ves- 
sel. For  small  work  on  the  foot  lathe  the  liandles 
of  the  tools  n(*ed  not,  b<‘  as  long  as  repn^sented, 
in  t'ig.  I7.‘>.  'I'Ik'  l(‘nglb  commonly  employed  for  wood 
turning  tools  will  answer. 

To  spin  a ling,  a mandrel  like  that  shown  in  Pig. 


HOME  MECHANICS  FOR  AMATEURS  167 


182  will  be  reciiiired.  A plain  flat  ring  placed  between 
the  shoulders  of  the  mandrel  is  pressed  upon  by  the 
roller  seen  above  the  mandrel  until  the  ring  assumes 
the  desired  form.  Napkin  rings  are  made  in  this  way. 


Fig.  190.  Base. 


Fig.  191.  Vase. 


Fig.  183  shows  a concave  reflector.  Fig.  184  represents 
a simple  cup  formed  of  two  pieces.  Fig.  185  represents 
a small  vase  made  of  three  pieces,  the  smaller  end  of 
the  upper  or  conical  part  and  the  upper  portion  of  the 


1C8 


HOME  MECHANICS  F()|{  AMATEUHR 


base  i)iece  l)eiiif>’  soldered  in  a sidierical  connecting 
piece.  Tlie  two  lialves  of  the  ball,  Eig.  18(!,  are  made 
upon  the  saine  form.  Tlie  edges  are  beveled  and  sol- 
dered together.  Tlie  i)itcher,  Thg.  tST,  is  made  of  five 
span  pieces,  a short  cast  and  turned  ])iece  that  nnites 
it  to  its  base,  and  a handle  made  of  s(piare  wire.  The 
card  receiver.  Fig.  188,  has  a span  top  and  base,  and 
a cast  standard.  The  Aase,  Fig.  18!),  consists  of  four 
spun  pieces  and  three  legs  of  S(piare  Avire,  uniting  the 
body  Avith  the  base.  Fig.  1!)0  shoAvs  a base  for  a mag- 
netic needle  or  other  small  apparatus,  hdg.  191  repre- 
sents a vase  composed  of  seA-en  span  pieces  and  tAvo 
handles  of  s<piare  Avire.  ^lore  comidex  (;xamples  of 
Avork  done  by  the  ]n'ocess  of  spinning  might  be  fur- 
nished. The  ones  giA'en  are  undoubtedly  sufficient  to 
enable  the  amateur  to  get  an  idea  of  the  endless  variety 
of  articles  that  may  be  made  by  this  simple  and  easily 
acquired  art. 


PART  lY. 

MODEL  ENGINES  AND  BOILEBS 

A HOME-MADE  STEAM  ENGINE 

A STEAM  ENGINE  carefully  made  is  a piece 
of  mecliaiiism  to  be  proud  of,  no  matter 
what  its  particular  design  may  be.  A 
double-acting  engine  of  good  proportion, 
with  a bored  cylinder  and  forged  crank  and  crank 
shaft,  and  other  parts  made  in  keeping,  is,  of 
course,  the  better  form  of  steam  engine  to  make,  but, 
as  we  are  presuming  that  not  every  amateur  has  the 
facilities  for  building  such  an  engine,  a description  of 
a simple  single-acting  engine  which  could  be  made  by 
any  boy  handy  with  tools  is  given.  It  can  be  made  a\  ith 
an  ordinary  light  foot  lathe,  as  no  boring  is  required, 
nor  is  there  any  turning  to  be  done  that  does  not  come 
Avithin  the  range  of  such  a lathe. 

A vieAV  of  the  engine  and  the  boiler  and  engine  is 
given,  and  also  a sectional  view  shoAving  the  construc- 
tion of  the  valve  and  valve-operating  cam,  and  the 
steam  passages  in  the  base. 

The  cAdinder  consists  of  a piece,  A,  of  mandrel-draAvn 
steel  tubing  (Avhich  needs  no  boring)  2^  inches  long 
and  i inch  internal  diameter.  The  thickness  of  the 
metal  forming  the  tube  is  tV  inch.  This  piece  of  tub- 
ing is  fitted  to  a boss,  a,  about  i inch  high,  formed 
on  the  brass  block,  near  one  end.  This  block  is  1^ 
inches  long  and  i inch  thick,  and  is  provided  Avith 
lugs  for  receiving  screws,  by  which  it  is  attached  to 
the  base  plate.  In  this  block  are  formed  the  steam 

[169] 


170 


WOMK  MKCIIAXICS  FOI?  AMATFUI^S 


l)assai>“(^Sj  h (%  and  valve  (‘lianilxa'.  Tliis  liol(‘  drillcMl 
from  tli(‘  front  backward  and  foianin<»’  tin*  ])assa|L»(*,  />, 
i'(H‘eives  tlu^  stcniin  sn])])ly  l)il>e,  H.  A liol(^  is  drilb'd 
from  tlie  rc^ar  (md  of  tlu^  block  forwai'd  to  a point 
about  o])posite  the  (‘ent(‘r  of  the  cvlimba*,  forming  with 
the  hole,  d,  the  steam  dm-t,  r*  d.  Near  tln^  r(‘ar  (md  of 
the  block  is  drilled  a tV  hoh^,  fi*om  Ixnnmth,  which 
forms  the  valve  seat,  c,  just  Ixwond  tlu^  ])assa,^(‘,  h.  A 
tV  inch  hole  is  startcxl  at  the  valv(‘  scmt,  c,  and  con- 
tinued to  the  to])  of  the  block.  This  smalhu'  hoh^  is 
counter-bored  from  tlu^  top  with  a in(*h  drill,  leav- 
ing* the  vahm  (diamber.  The  counter-borcxl  jx)rtion  of 
this  hole  receives  the  plug,  /,  which  is  bored  longitudi- 
nally to  receive  the  valve  stem,  //,  of  the  conical  valve, 
e'.  The  valve  stem  is  about  3}  inches  long,  and  is 
provided  with  the  adjustable  collai*,  //,  between  whicdi 
and  the  plug,  /,  is  placed  a spiral  spring  which  tends 
to  keep  the  valve  normally  closed.  The  steam  pas- 
sages, 1)  and  c,  are  closed  with  screw  plugs,  as  shown. 

To  the  steel  tube  which  forms  the  cylinder  is  fitted  a 
piston  of  cast  iron.  It  is  about  1^  inches  long  and  is 
packed  by  the  steam  or  water  contained  in  the  grooves 
in  the  piston.  The  upper  end  of  the  piston  is  slotted 
to  receive  the  loAver  end  of  the  connecting  rod,  which 
is  pivot(xl  tlnu'ein  upon  a ^-inch  pin  passing  through 
the  piston  and  lower  end  of  the  connecting  rod,  as 
shown  in  dott(xl  lim^s  in  the  sectional  view. 

Tlie  brass  blo(‘k  whi(‘h  supports  the  cylinder  has 
lugs  on  op]X)sit(^  sid(‘s  rcxxdving  screws  wdiich  pass 
tlii'ougli  tli(*m  into  base  ])late.  Tliis  plate  is  4 
incli(*s  w id(^,  5 incli(‘s  long  and  i iin^h  thick.  At  the 
r(*ar  of  I lx*  valve*  chamb(*r  is  a post  fornuxl  of  a -l-iiudi 
scpiare*  brass  rod  IJJ  inches  long,  securcxl  to  the  base 


HOME  MECHANICS  FOE  AMATEUES  171 


plate  by  a screw  passing  upward  through  the  plate 
into  the  end  of  the  post.  A similar  post  is  placed  near 
the  rear  end  of  the  base  plate.  The  ends  of  the  posts 
are  squared  in  the  lathe.  Both  posts  are  bored  trans- 


Fig.  192.  Simple  Steam  Engine. 

versely  near  the  top  to  receive  the  shaft,  which  is  ^ 
inch  in  diameter  and  5 inches  long.  The  space  be- 
tween the  posts  is  2 inches,  and  the  distance  between 
the  shaft  and  base  plate  is  inches.  On  the  shaft, 
between  the  posts,  is  placed  the  iron  fly-wheel,  which  in 


172  HOME  MI'X'IIANIOS  FOIt  AMA'I’HKUH 


the  present  ease'  consists  of  an  old  valve  wheel  41  inches 
in  diameter,  hashed  to  lit  the  shaft  and  fastemsl  Avith 
a set  screw. 

The  (‘11(1  of  the  shaft  which  ])rojects  lu'yond  the  ])()st 
OA‘er  the  cylind(*r  carri(‘s  a |-inch  crank  on  which  is 
placed  a conne(*tinf>’  rod.  This  rod  ni(‘asni'(‘s  If  inch(*s 
betAveeu  tlie  centers  of  the  holes  for  the  crank  ])in  and 
the  ])in  in  the  ])iston. 

In  the  side  of  the  cylinder  are  drilled  thr(‘e  iV  ineli 
holes  in  a horizontal  line,  and  close  tos>eth(‘r  to  foian 
the  exhaust  jiort  of  the  (‘njiiiu*,  Avhich  is  (‘ntirely  nn- 
coA'ered  hy  the  ]nston  avIk'ii  it  is  in  the  position  shown 
in  the  eiij’ravinf^.  The  exhaust  r(‘niains  op(*n  for  about 
a (piarter  of  the  reA'olution.  This  jiort  is  left  exposed 
for  clearness,  but  it  may  he  covered  hy  a hollow  ring 
Avhich  encircles  the  cylinder  and  receives  an  exhaust 
pipe. 

On  the  left  shaft  is  placed  a cam,  in  whose  boss 
there  is  a circumferential  groove,  and  upon  the  upper 
end  of  the  valve  stem  is  placed  a fork,  the  upper  ends 
of  Avhich  slide  in  the  groove  in  the  boss  of  the  cam.  A 
stud  inserted  in  the  fork  has  upon  it  a roller  which 
rolls  on  the  higher  part  of  the  cam  and  opens  the  Anlve 
at  the  prop(*r  instant.  This  cam  opens  the  valve  just 
before  the  piston  reaches  the  lower  limit  of  its  stroke, 
and  allows  the  valve  to  close  just  before  the  exhaust  is 
op(‘ne(l  by  the  piston. 

4'he  boiler  of  this  engine  consists  of  a copper  float  to 
b(‘  found  in  the  niark(‘t,  ma(l(‘  by  an  electrolytic  de- 
posit of  coj)])er.  Such  a,  float  forms  a seandess  boiler 
ca])abl((  of  withstanding  a gr(“at  j)ressure,  say  100 
y»(»nn(ls.  The  Ixtilcr  is  mounted  in  a tri])0(l  made  of 
band  iron  and  is  furnislu'd  with  a safety  valve  ^ inch 


HOME  MECHANICS  FOK  AMATEUES 


173 


in  diameter,  the  lever  of  which  is  about  2 inches  long, 
and  graduated  and  weighted  so  that  it  will  blow  off  at 
35  pounds,  thus  insuring  perfect  safety.  (The  ordinary 
copper  float  is  not  recommended.)  A brass  steam  pipe, 
I inch  internal  diameter,  is  screwed  into  the  safety 


Fig.  193.  Simple  Steam  Engine. 

valve  casing  below  the  valve  sat,  and  has  at  its  end  a 
miniature  angle  valve  which  is  connected  to  the  engine 
by  the  inclined  pipe,  and  by  elbow  and  nipple  which 
extends  into  the  base.  As  the  angle  valve  is  a trouble- 
some piece  of  work,  an  ordinary  stop  cock  is  recoin- 


174  IlOiMK  MECHANIC'S  EOlJ  A.MATKIMIS 


in(Mi(l(Ml  in  its  stead.  It  slionid  l»(‘  ])lac(“d  in  tlie  in- 
clined ])i])e. 

Tile  best  Imrner  for  tliis  boilin'  is  an  Arn^and  jjas 
Itnnsen  burner  like  that  sliown.  Of  course  an  aleoliol 
lam])  \yill  answer,  bnt  it  is  not  as  safe  as  the  "as 
bnriier. 


Itolli  enj>ine  and  boiler  shonld  be  mounted  on  a 
suitable  basi*  board. 

The  engine  is  capable  of  inakiu"  a thousand  or 
twelve  hundred  revolutions  jier  minute.  It  must  be 
well  balanced  for  Ibis  si>eed. 


HOME  MECHANICS  FOR  AMATEURS  175 


The  boiler  is  filled  when  cold  through  the  safety 
valve  opening  by  means  of  a funnel  having  a slim  cor- 
rugated tube.  The  boiler  should  be  about  two-thirds 
full  of  water  at  the  start. 

It  is  obvious  a larger  engine  could  be  made  on  the 
same  principle;  but  the  front  support  for  the  shaft 
should  be  made  A-shaped  and  placed  next  to  the 
crank,  and  the  cam  should  be  placed  between  the  sup- 
port and  the  fly-wheel ; the  shaft  support  would  then 
extend  over  the  cylinder-base. 


A SAFE  WAY  TO  RUN  A SMALL  ENGINE 

Almost  every  youth  at  some  time  in  his  life  has 
coveted  a steam  engine,  or  some  other  motor  having 
energy  and  ability  to  move  of  itself  and  to  impart  mo- 
tion to  other  machines,  but  through  fear  of  fire  from 
the  lamp  used  to  generate  steam,  or  anticipating  pos- 
sible explosions,  has  been  obliged  to  forego  the  pleasure 
of  being  a boy  engineer,  and  seek  amusement  in  other 
directions.  Every  boy  can  own  a steam  engine,  since 
one  can  be  purchased  for  50  cents,  fl,  |2  or  more,  and 
the  engine  can  be  run  with  safety  by  means  of  com- 
pressed air.  Any  engine  that  will  run  by  steam  will 
run  equally  well  with  compressed  air. 

Rut  how  is  the  compressed  air  to  be  furnished  and 
stored  for  use?  There  are  very  few  families  without 
bicycles,  and  every  bicycle  requires  a pump  for  in- 
flating the  tire;  why  not  use  the  same  pump  to  com- 
press air  for  an  engine?  The  boiler  constitutes  a small 
reservoir,  and  an  auxiliary  reservoir  may  be  connected 
with  the  boiler  by  means  of  a small  rubber  tube.  The 
auxiliary  reservoir  may  consist  of  a piece  of  strong 


17G 


TIOMK  MfiCTTANTCS  FOR  AMATEURS 


3-incli  s<ilvanize(l  iron  leader,  with  caps  soldered  on  the 
ends,  with  a small  tube  inserted  at  any  (*onv(mient 
point  to  receive  a bicycle  valve,  and  another  small 
tube  to  receive  the  piece  of  small  rnl)ber  tnbinj]^  which 
forms  the  conne(*tion  between  the  reservoir  and  the 
engine  or  the  boiler  belonging  to  the  engine. 

This  boiler  and  reservoir  when  pnm])ed  np  as  mnch 
as  possible  by  ordinary  exertion,  will  run  the  (mgine 
while  driving  the  boat  for  about  15  minntes.  The  (‘aps 
to  the  reservoir  mentioned  are  made  conical  so  that 
the  reservoir  may  be  drawn  in  the  water  after  the  boat, 
the  connecting  rubber  tube  forming  the  hawser  for  tow- 
ing the  reservoir. 

If  it  is  desired  to  rnu  a stationary  engine  with  com- 
pressed air,  the  reservoir  may  consist  of  a tin  can.  A 
1-gallon  varnish  can  answers  very  Avell,  bnt  it  can  he 
forced  out  of  shape  and  even  exploded  unless  it  is  en- 
cased in  a strong  wooden  box  fitting  it  closely  and  put 
together  with  screws. 

A MINIATURE  CALORIC  ENGINE 

The  hot  air  engine  is  not  a very  recent  invention.  A 
number  of  engines  of  this  class,  of  different  sizes,  were 
devised  and  nse<I  in  the  early  part  of  the  present  cen- 
tury, and  in  the  latter  part  of  the  last  century  there 
were  in  existence  engines  constructed  to  be  operated  by 
the  expansion  of  air. 

Nothing  in  the  way  of  a motor,  aside  from  a wind- 
mill or  wat(*r  wh(“(‘l,  can  he  more  simple  than  this,  and 
it  is  a pity  ihat  it  is  not  cai)ahl('  of  moi'e  general  ap- 
])Iica(ioti.  M(»tors  of  tliis  kind  have  Ikkui  used  to  some 
exieiit  for  driving  ligld,  machin(‘i-y,  and  they  have  been 
largely  employed  in  pumping  wat(“r. 


HOME  MECHANICS  FOR  AMATEURS  177 


Quite  recently  caloric  engines  have  been  made  in  the 
form  of  a toy,  as  illustrated  in  the  following  engrav- 
ing. In  the  motor  here  shown,  the  air  contained  in 
the  expansion  cylinder  is  alternately  heated  and  cooled, 
and  no  fresh  air  is  introduced.  This  action  is  so  rapid 


Fig.  195.  Small  Caloric  Engine. 


ns 


IIOMI*;  MKCIIAXICS  KOI;  A,MA'l’h:ri;S 


ill  a small  (“iinim*  tlial  Ilia  ci-ank  sliafi  can  make  (lOO  or 
70(1  rcvoliilioiis  a miimlc.  in  cxamiiiini-  Hu*  sectional 
vi(“\\s  (2,  ;?  ami  4,  K’ifi'.  100)  a j^ood  idea  of  the  e(mstrne- 
tion  and  operation  of  the  motoi-  may  he  ohtaiiH'd.  In 


P^iG.  19f).  Sectional  Views  of  Small  Caloric  Engine. 


l)ri(*r,  tli(^  lari»(‘i‘  and  lonj^ca*  of  tlie  two  (‘vlinders  (the 
(expansion  cyliinh*]*)  contains  a lon<>‘,  Iiollow  piston 
call(*d  I ‘d  ransIVi*  pislon-’  wlii(‘li  fils  1 he  (‘vlindca'  very 
loos(dy.  1\)  lliis  |)islon  is  at(a(‘li(Ml  a I'od  (\\l(nulint>‘ 
I liron^^li  a clos(*  iii  I ifii;  sI(m*v(‘  in  tln^  iop  of  ilu^  cylinder^ 


HOME  MECHANICS  FOE  AMATEUES  179 


the  piston  rod  being  provided  witli  a connecting  rod 
fitted  to  the  crank  at  the  middle  of  the  shaft.  The  up- 
per part  of  the  expansion  cylinder  is  furnished  with  a 
Avide  flange  forming  a cap  Avhich  fits  over  the  sheet  iron 
fire  box,  and  to  the  top  of  the  expansion  cylinder  are 
secured  the  standards  in  Avhich  is  journaled  the  crank 
shaft. 

To  the  flange  is  attached  the  jiOAver  cylinder,  Avhich 
is  shorter  and  smaller  in  diameter  than  the  expansion 
cylinder.  This  cj’Iinder  is  provided  Avith  a piston  to 
Avhich  is  pivotally  connected  the  loAver  end  of  a connect- 
ing rod,  the  upper  end  of  Avhich  receives  a crank  pin 
projecting  from  one  of  the  fly  AA’heels  at  right  angles  to 
the  transfer  piston  crank.  A hole  bored  in  the  flange 
connects  the  expansion  cylinder  and  the  bottom  of  the 
power  cylinder,  as  shoAvu  in  No.  2,  Fig.  190,  and  the 
outer  end  of  the  hole  is  stopped  by  screAV  plug  Avhich 
can  be  removed  for  cleaning  the  hole,  should  it  become 
stoi)pod  by  oil  or  other Avise. 

An  alcohol  lamp  is  provided  for  heating  the  expan- 
sion cylinder,  it  being  placed  in  position  to  heat  the 
loAver  end  of  the  cylinder,  as  shoAvn  in  the  larger  view. 
The  top  of  the  lamp  is  provided  Avith  a hemispherical 
cavity,  at  the  bottom  of  Avhich  is  the  aperture  for  filling. 
The  stopper  consists  of  a marble  dropped  into  the 
hemispherical  cavity  and  serA'ing  the  double  purpose  of 
stopper  and  safety  valve. 

The  expansion  and  poAver  CAdinders  contain  a certain 
amount  of  air  Avhich  is  neA’er  changed  during  the  op- 
eration of  the  engine,  except  by  expansion  and  contrac- 
tion. Heat  having  been  applied  to  the  loAA’er  end  of 
the  expansion  cylinder,  the  engine  is  started  by  giving 
the  crank  shaft  one  or  tAA’o  turns  in  the  direction  indi- 


180  TIOJMI^  IMKCIIANICS  FOK  A:yiATFlIRS 


oated  hy  tlie  ari'ows  on  tin*  rims  of  tlu^  fly  wlnuds.  Tlie 
air  at  tlu^  io])  of  ilie  (\x])ansion  (‘vlimha*  is  lransf(a*r(*(l 
to  tlie  lower  end  of  tln^  (*vlind(a'  by  tli(‘  fransf(*]‘  ])iston 
as  it  rises;  at  tlie  sanu^  tinu*  ])ow(a'  ])islon  (b^seimds, 
and  by  this  time  tlie  air  is  lu^atcMl  in  fli(‘  lower  ]>art  of 
the  ex])ansion  cylinder  and  be;L;ins  fo  (‘xjiand.  The 
])ower  ])iston  is  in  position  to  be  ])nsh(Ml  nj)  by  the  air 
pressure.  As  the  ])ower  jiiston  reaeln^s  the  n])])(a‘  (Mid 
of  its  stroke,  the  ti*ansfVr  piston  dc^secMids  and  transf(M‘s 
the  heated  air  to  the  n])i)er  end  of  the  (Mxjiansion  (*ylin- 
der,  where  it  is  cooled,  thus  r(Hln(Mni>’  the  ])r(‘ssnr(^  and 
allowino^  the  ])ower  ])iston  to  desc(Mid  ai>ain.  This  op- 
eration is  ri^peated  at  every  stroke.  It  is  almost  impos- 
sible to  believe  that  the  air  can  be  heated  and  cooled 
so  rapidly. 

The  efficiency  of  the  motor  can  be  increased  by  sur- 
rounding the  upper  portion  of  the  expansion  cylinder 
by  a Avater  jacket  provided  Avith  a Avater  supply  pipe 
at  the  bottom  and  a discharge  pipe  at  the  top,  as 
shoAvn  in  No.  5,  Fig.  lOb,  and  keeping  a continual  floAV 
of  cool  Avater  through  the  jacket.  When  the  motor  is 
used  for  pumping,  the  Avater  is  forced  through  the 
jack(d. 

This  little  motor  is  only  a toy,  but  it  A^ery  completely 
illustrat(^s  the  princi])le  of  one  of  the  most  successful 
hot  air  enginc^s  (wer  deviscnl.  ‘ If  the  reader  is  mechan- 
ically inclin(‘d,  he  may  make  a motor  on  this  plan  on  a 
nimdi  lai‘g(M'  S(‘ale,  and  us(^  it  for  driving  macdiincuw. 
Th(M'(‘  can  b(‘  no  doubt  about  its  siuMM^ssful  construc- 
tion or  o])(M'ation,  if  it  is  mad(^  airtight  and  the  bear- 
ings and  friction  sni‘fa(*(‘s  ai'(‘  made  to  run  frcH^  The 
j)ro|)ort ions  may  b(^  about  tlu^  same  as  shown  in  the 
cnt. 


HOME  MECHANICS  FOK  AMATEURS  181 


The  dimensions  of  tlie  motor  from  wliieli  the  views 
were  made  are  as  follows: 

INCHES 

Length  of  expansion  cylinder 4f 

Internal  diameter  of  expansion  cylinder li\ 

Length  of  transfer  piston 2\i 

Diameter  of  transfer  piston 1^ 

Length  of  power  cylinder If 

Diameter  of  power  cylinder fi 

Lengtli  of  cranks tV 

Diameter  of  fly  wheels 3 

Height  of  firebox  from  base.  5^ 

AN  INEXPENSIVE  WATEK  iMOTOR 

A simple  but  A’ery  effective  water  motor  can  be 
made  by  any  one  according  to  the  plan  here  shown, 
Avith  little  trouble  or  expense.  It  may  be  necessary  to 
have  a few'  minutes’  Avork  done  by  a tinsmith.  The 
maker  may  do  this  if  he  understands  soldering. 

In  a pine  board  7 inches  square  and  1 inch  thick,' 
make  a round  hole  5 inches  in  diameter,  by  the  use  of 
a scroll  saAv,  or  in  any  other  convenient  Avay.  To  the 
sides  of  the  board  fit  tAvo  thin  boards  f inch  thick, 
one  on  either  side.  In  a small  hole  in  the  center  of 
each  side  drive  a short  piece  of  brass  tube  of  about  | 
inch  internal  diameter,  and  to  these  tubes  fit  a straight 
steel  wire  so  that  it  will  revolve  freely.  This  wire  is 
the  shaft  of  the  motor  Avheel.  It  should  be  of  sufficient 
length  to  project  an  inch  beyond  its  bearings,  to  receive 
a small  pulley. 

To  the  center  of  the  shaft  is  soldered  a sheet  brass 
disk  3 inches  in  diameter,  so  that  it  Avill  run  true  as 


182 


iroMK  iMKdIANICS  FOR  AMXVVA'U^ 


ili(‘  sliafi  T'(‘V()lv(*s,  and  lo  llin  disk  is  snld(*r(*d  a disk  of 
brass  wir(^  i>anz(‘  »>()  ni(‘sli.  1dH‘  (*d<»(*s  of  tin*  bi'ass  wiiH^ 
gaiizo  iiiustj  as  lln^  ladic^s  would  say,  lx*  s(nv(Ml  ov(a*  and 
ov(‘r  witli  a iuw  (*o])])(‘r  wiix^,  to  ])r(‘V(‘nt  it  from  ravcding 
A^dlen  tlu^  AvluHd  r(^volv(‘s  rapidly.  If  tlu‘  workman  is 
an  adei)t  In^  may  soldcu'  a rini»  of  brass  wire,  say  No. 
18  or  No.  20,  to  the  edge  of  the  wire  elotli. 


Fig.  197.  Motor  Driving  Sewing  Machine. 


Th(^  simplest  Avay  to  secure  a nozzle  for  tlie  Avheel  is 
to  l>ny  a ch(‘a]),  small  oil-c'an  having  a long  nozzle,  witli 
an  ofxming  in  tln^  small(‘r  (md  of  about  tV  inch.  This 
nozzh^  is  ins(*rt(‘d  inlo  tln^  (xlgc^  of  the  Avooden  Avlieel- 
cas(‘,  as  shown,  and  iis  smalhu'  cmd  is  Ixmt  so  that  it 
forms  a small  angh*  with  lln^  A\di(X‘l,  Avilh  the  point  of 
tln‘  nozzl(‘  as  m*ar  lln*  wir'(‘  (dolh  as  ]x)ssible  Avithont 
loiicliing.  To  (‘ans(*  lln*  wh(M*l  Ihns  madcHo  k(X^])  a cen- 


HOME  MECHANICS  FOE  AMATEUES  183 

tral  position  in  its  case,  pieces  of  the  small  tube  before 
named  may  be  slipped  on  the  shaft  each  side  of  the 
wheel. 

A f-inch  hole  may  be  made  in  the  casino  at  the  bot- 
tom, and  provided  with  a short  tube  for  receiving  a rub- 


Fig.  198.  Small  Water  Motor. 


ber  pipe,  to  carry  off  the  waste  water,  and  there  slionld 
be  a -|-inch  hole  in  each  side  near  the  top  to  admit  air. 
The  casing  may  be  secured  to  the  wooden  foot-pieces 
with  screws.  It  is  desirable  to  make  the  casing  im- 
pervious to  water.  To  do  this,  the  various  parts  may 
be  boiled  in  hot  paraffine  for  ten  minutes.  If  it  is 


184  HOMJ-:  MECHANICS  EOIJ  AlIATEUES 


found  difficnli.  to  socnro  ])in‘nninc  in  bulk,  a ])onn(l  of 
parattine  caiidlos  will  fni-nisli  (■non”li  for  ibis  ])ni-])os(*. 
Tlio  inHaniinabb*  na1ni-e  of  ])ai-aflin(“  sbonbl  be  ke])t  in 
mind,  and  a cover  slionld  be  ])rovided  for  the  v(>ssel  in 
wliicb  it  is  ni(“Ifed,  so  lliaf  if  may  instanfly  l»e  (‘xfin- 
gnislied  by  the  covei'  slionld  it  b(‘com<‘  innifi'd.  The 
metal  used  in  the  conslrncl ion  of  this  wheel  should  bi^ 
of  brass,  exce])tinf>-  the  shaft.  Tin*  sci-ews  with  which 
the  casing'  is  put  toi>ether  should  be  brass.  The  toji  of 
the  oil-can  is  cut  olf  to  form  a ]»art  of  the  coipdinn'  for 
receiving*  the  rubber  jiipe  leading  from  the  wash-bowl 
faucet  to  the  motor. 


Fig.  199.  Diagram  Showing  Position  of  Nozzle. 


To  prevent  the  checking  of  the  v ooden  parts  of  the 
inotoi-,  tlie  parts  should  be  arranged  with  the  grain 
lying  in  the  same  direction. 

AVitli  sufficient  water  pressure,  this  motor  will  make 
from  1,500  to  2,000  revolutions  per  minute.  With  a 
A (aw  ll(a\il)l(i  coi'd  1x^1 1 — a leather  shoestring,  for  ex- 
amphj — it  laay  b(‘  mad(^  to  drive  a light  sewing  machine, 
fan,  oi*  any  otlua*  macliim^  recpiiring  a small  amount 
of  ])ow(a' 

If  moi‘(‘  ])ow(‘r  is  ]‘(*(|uir(‘d  Ilian  can  be  secured  by  one 
j(‘l,  addil ional  nozzl(*s  may  b(‘  distributed  around 
\\'lie(d,  oi*  moiM^  w1i(m*Is  may  be  jdaced  on  the  same 


HOME  MECHANICS  FOR  AMATEURS 


185 


shaft,  but  nothing  will  he  gained  unless  the  water 
pressure  is  maintained.  This  pressure  should  be  from 
25  to  40  pounds  per  square  iueh. 

In  a small  high-speed  motor  of  the  class  here  de- 
scribed, the  full  power  is  realized  only  when  it  is  pro- 
vided with  a very  small  pulley  connected  bj^  a very 
flexible  belt  with  a large  pulley  on  the  machine  to  be 
driven. 

It  is  obvious  a non-corrosive  metallic  case  would  be 
better  than  a wooden  one,  and  the  metal  one  is  advised 
when  the  builder  has  conveniences  for  making  a casing 
of  that  kind. 


» 


4 


) 


.S.-' 


. I 


— k 


...  Ji  sJt 


I 


PART  Y. 

METEOROLOGY 
SELF  RECORDING  INSTRU:\rENTS 


IF  these  instruments  Avere  constructed  so  that 
each  would  produce  a permanent  record  of 
.its  movements,  it  would  certainly  add  to 
their  usefulness  as  well  as  their  convenience, 
but  it  is  thought  best  to  confine  the  construction 
to  these  simple  forms  of  apparatus,  trusting  to 
the  ingenuity  of  the  reader  to  apply  clock  mechanism 
for  keeping  the  records.  One  eight-day  clock  could  be 
made  to  do  duty  for  all  the  instruments.  It  could  be 
geared  to  a drum  so  that  it  Avould  make  one  revolution 
in  one  day,  or  in  one  Aveek,  and  each  instrument  could 
be  made  to  mark  on  a piece  of  paper  carried  by  the 
drum.  The  paper  Avould  need  to  be  graduated  so  that 
the  pen  carried  by  each  instrument  could  be  readily 
traced.  There  should  be  divisions  for  duA’S  and  hours. 

t/ 

The  pen  by  Avhich  the  record  is  made  is  simply  a 
small  glass  tube  about  ^ inch  in  internal  diameter, 
A\’ith  the  end  Avhich  bears  upon  the  paper  draAvn  out  to 
almost  a capillary  tube  and  cut  off  and  made  round  and 
smooth  by  heating  in  a gas  or  alcohol  flame.  The  ink 
used  in  this  pen  is  a drop  of  red  ink  mixed  Avith  an 
equal  amount  of  glycerine.  This  ink  remains  in  the 
narroAver  end  of  the  tube  and  does  not  evaporate. 

METEOROLOGY 

The  subject  of  meteorology  has  claimed  the  atten- 
tion of  men  to  a greater  or  less  extent  doubtless  since 

[187] 


188  HOME  ]\IE(MIANICS  FOl?  AMATKUFS 


<()  1)(‘  iiilial)il(‘<l  hy  Ininiaii  l)(*iii<;s.  TIi(‘ 
])h(ai()iiuaia  of  tlic^  air  iniisl  liav(‘  (*arly  atli'actcMl  atl(‘ii- 
tioii  and  (‘aus(‘d  tli(‘  ()l)S(a-v(*rs  to  i'(‘ason  fi'oni  rausc*  to 
cdt‘e('t  nntil  ('ani(‘  <>radiially  to  an  nnd(‘r- 

standinj>  of  eartli,  air  and  watca- — not  always  ronxx-t — 
but  in  tlie  main  ])oinlin<>  to  tli(‘  ])i'(‘S(‘nt  d(‘V(^lo])ni(mt 
of  tile  S(‘ien('e,  so  that  aft(‘r  tln^  la])S(^  of  many  c*(*ntnri(‘s, 
the  (dose  stmbmt  of  nature  is  abb^  to  (explain  various 
])lienomena  and  to  jircxliet  Avitb  moix^  or  b^ss  (-(‘rtainty 
what  will  ba])])(m,  (^sjxHdally  in  tln^  immcHliate  future. 

To  be  able  to  jnxxliet  the  weatlna^  Avitli  a little  more 
certainty  than  the  ordinary  ^Sv(‘ath(n*  ])i'0])li(d’^  (‘an  do, 
the  student  should  lie  in  communication  with  the  (lov- 
ernment  Weather  Bureau,  so  as  to  avail  himself  of 
the  ()bs(u*vations  of  others;  but  cw(ui  Avithout  such 
facilities  as  these  many  interesting  observations  may 
lie  made  Avith  the  simple  apparatus  hereinafter  de- 
scribed, and  notes  iiiaA^  be  kept  for  future  reference. 

This  kind  of  obseiwation  is  instriu'tive  in  seA^eral 
Avays.  The  A^ery  act  of  making  frequent  obserA^ations 
induces  a methodical  habit  Avhich  Avill  be  Amluable 
through  lif(^,  and  the  obseiwations  are  interesting  and 
instructive  in  themseh^es.  Besides  all  this,  the  record 
formed  is  likelj^  to  be  Amluable  for  both  present  and 
future  use. 

WHAT  :\rAA^  P>E  LEAliNEl)  BY  THE  USE  OF  THE 
HETEOBOLOtMCAL  INSTBUMENTS 

\\'(^  find  lh(‘  w(‘aih(U‘  vam^  ])()inting  toAvard  the 
AV('st  w(*  look  for  ( b‘ar  w(‘alh(M‘,  and  as  a I'ule  Ave  are 
not  disa})iioinl(*d  ; bid  w li(*n  fh(‘  van(‘  in(li(‘at(^s  that  the 
wind  is  lilowing  from  tlu^  (‘asf,  a storm  is  expe(‘te(l. 


HOME  MECHANICS  FOR  AMATEURS 


189 


^VTien  it  blows  from  the  north,  cool  Aveather  may  be 
looked  for,  and  A\dien  it  blows  from  the  south,  it  hardly 
ever  fails  to  bring  sultry  days  in  summer  and  thaAvs 
in  Aviuter. 

When  the  Avind  bloAvs  strong  from  any  direction, 
curiosity  is  aroused  as  to  the  pressure  it  is  exerting. 
This  may  be  ascertained  by  observing  the  Aviud  pres- 
sure gauge ; pounds  pressure  shows  that  the  Avind  is 
blowing  fifteen  miles  per  hour ; pounds  pressure  per 
square  foot  represents  a A’elocity  of  thirty  miles  per 
hoAir;  18  pounds  pressure  indicates  a A'elocitA^  of  sixty 
miles  an  hour,  and  50  pounds  pressure  is  registered 
during  a tornado  one  hundred  miles  an  hour.  In 
calculating  the  pressure  as  indicated  by  this  gauge 
it  must  be  remembered  that  the  board  Avhich  offers 
resistance  to  the  Avind  has  only  a half  square  foot 
area. 

The  A'elocitA’  of  the  Avind  is  shOAvn  bv  the  anemometer. 
Wind  is  hardlv  noticeable  Avhen  it  bloAVS  a mile  an 
hour.  When  it  blows  fiAe  miles  an  hour  it  is  a pleas- 
ant breeze;  Avhen  it  bloAVS  ten  miles  an  bour  it  is  a 
brisk  breeze;  Avhen  it  blows  at  a twenty-mile  rate  it  is 
a stiff  breeze;  at  thirty  miles  it  is  a high  wind,  and  at 
forty  miles  it  is  a A*ery  high  AA’ind.  At  eighty  miles  it 
is  a hurricane,  and  at  a hundred  miles  per  hour  it  is 
a tornado. 


THE  WEATHER  VANE 

The  weather  Amne  hardly  needs  explanation  to  make 
it  understood.  In  the  top  of  a stout  pole  is  inserted 
a ^-inch  rod  Avhich  is  Idnntlj"  pointed  at  its  upper 
end.  On  this  is  placed  a A'ane  consisting  of  a Avedge- 
shaped  piece  of  hard  Avood  Avith  a hole  through  it,  a 


190 


IIOMK  MKCMIAXK^S  VOU  \^\\TVA:\l^ 


])i(‘(‘(^  of  liooj)  iron  Ixmiii;  fasl(*n(*(l  ov(*r  tin*  liol(*  and 
i'0stin<>  on  tln^  n])])(‘r  (‘inl  of  tin*  l)lnnl-])oinl(‘(l  I'od. 


of  j-incli  l)oard  4 iindn^s  wid(‘  and  20  incln^s  lonu. 
Tliose  i)i(‘(‘(‘S  ar(‘  1(4  into  tin*  facets  of  tli(‘  so 


Fig.  200.  Weather  Vane. 


so  that  their  fri^e  ends  are  al)out  24  inches  apart. 
Til  is  construct  ion  insures  steadiness. 

Tile  thin  end  of  the  wedge  has  an  arrow-headed  arm 
])rojecting  from  it  to  indicate  the  direction  of  the 
wind.  In  the  sides  of  the  pole,  near  the  upper  end, 
are  inserted  four  rods  arranged  at  90  degrees 

with  each  other,  and  in  slots  sawed  in  the  ends  of  the 
rods  are  riveted  letters  which  indicate  the  points  of 
compass,  N.,  S.,  E.  and  W.  These,  in  connection  with 
the  arrow-h(nid(Ml  arm,  enable  the  observer  to  tell  which 
way  th(i  wind  blows. 


WIND  PKESSURE  GAUGE 


Th(‘  (‘onsf  land  ion  of  a wind  pressure  gauge  is  as 
simple^  as  that  of  th(i  ordinary  windmill,  whicdi  every 
hoy  knows  hoW'  to  mak(\  A w ind  van(‘  0 imdies  Avide 
ami  24  im  ln^s  long  is  mad(‘  of  a board,  on  tln^ 


HOME  MECHANICS  FOR  AMATEinJS 


191 


edge  of  which  is  secured  a piece  of  band  iron  which  pro- 
jects over  the  end  of  the  hoard  about  11  indies.  In  the 
end  of  the  board  are  inserted  two  screw-eyes  for  receiv- 
ing the  rod  upon  which  the  vane  swings.  The  upper 
end  of  the  rod  is  pointed  bluntly,  so  that  the  piece  of 
hand  iron  which  rests  upon  it  allows  the  vane  to  swing 
freel}^  in  any  direction. 

The  middle  portion  of  the  board  is  cut  away  from  the 
upper  edge  to  admit  of  placing  a spring  scale  for  the 
measurement  of  the  wind  pressure.  In  the  upper 
edge  of  the  board  at  opposite  ends  of  the  scale-notch 
are  inserted  wire  screw-eyes  to  receive  the  horizontal 
wooden  rod  which  carries  the  wind-pressure  board,  8 
by  9 inches  long  and  | inch  thick. 

The  hoard  is  stiffened  by  a cleat  on  the  hack,  which 
is  bored  to  receive  the  rod.  A screw  hook  is  inserted 
in  the  rod,  and  another  is  inserted  in  the  upper  edge 


of  the  vane  for  receiving,  respectively,  the  eye  and 
hook  of  the  scale.  The  spring  scale  is  adjusted  so  as 
to  hold  the  thin  board  a little  more  than  the  length 
of  the  slot  in  the  spring-scale  away  from  the  pivot 
of  the  vane  when  the  wind  is  light  or  nil.  When  the 
wind  Idows  the  vane  keeps  the  instrument  headed 


102 


IlOMK  MK(MIANI(^S  YOU  AMATKUIJS 


toward  tlie  wind,  and  tl)(‘  s('al(‘  indi(‘at(‘s  fli(‘  ])r(‘ssnr(‘ 
on  a lialf  S(|nar(‘  foot,  so  lliat  lli(‘  r(*adin,!Lj^  innst  Ixi 
nnilti])li(‘d  by  2 to  S(M-ni‘(‘  a (‘oi'ixxd  ])i'(*ssnr(‘. 

Tlie  I'od  slionld  ins(ad(‘d  in  a ri<;id  ]x)st  and  ninst 
1)0  oxac'tly  vcndic'al. 

Tlie  amount  of  rain  fallin<>*  in  a iL»iv(m  tinu*  (‘an 
Ix^  as(*(a‘tain(Ml  a])])roximately  by  ])la(‘in,<;*  any  bind  of 
v(^ss(d  lia\inj»’  ])arall(d  sid(‘s  out  of  doors  in  an  o]x*n 
])la(X'  wlun'e  it  may  r(X‘(Mve  all  tln^  rain,  and  tlxm 
measnrinf>‘  the  d(‘|)tli  of  tlie  wat(‘r  after  the  rain  by 
nutans  of  a small  sti(‘k  ])lnn^(xl  into  it;  th(‘  depth 
beini>'  r(\i>istered  by  the  w(d  jxirtion  of  the  sti(‘k.  This 
method,  howcwer,  is  ernde  and  op(m  to  objcx'tions ; 
some  of  the  water  will  sjiatter  over,  some  will  be  lost 
by  evaporation,  and  some  will  be  displaced  by  the 
stick. 

If  the  observer  is  really  in  earnest  he  should  make, 
or  have  made,  a copper  vessel  like  the  one  shown  in 
the  illustration.  It  is  4 inches  in  diameter  and  b 
inches  high,  with  the  bottom  set  in  1 inch  so  as  to 
receive  the  copper  tube,  Avhich  is  bent  twice  at  right 
angles,  with  its  inner  end  inserted  in  the  recessed  bot- 
tom and  its  outer  end  extended  np  outside  the  vessel, 
and  even  with  the  bottom  to  receive  a |-inch  glass 
tnlx^,  which  is  (‘eniented  therein  with  a cement  consist- 
ing of  white  lead  i)aint  and  litharge  formed  into  a soft 
jiiitly. 

The  glass  tube  is  7 inches  long,  and  furnishes  a 
r(‘ady  m(*ans  of  asc(‘rtaining  the  d(^])th  of  water  in 
11i(‘  v(^ss(d  wlnm  viewcxl  in  (‘onmx'tion  with  the  S(‘ale 
of  in(*li(*s  alla(‘li(*d  lo  tin*'  v(‘SS(‘l. 

In  th(‘  joj)  of  lli(‘  v(‘SS(‘l  is  ins(‘rl(‘d  a fumud  84  iiu'hes 
long,  wdlli  a cylindri(*al  poi'lion  at  the?  top  2 inches 


HOME  MECHANICS  FOR  AMATEURS 


193 


deep.  The  upper  and  lower  edges  of  the  main  vessel 
are  wired  to  give  them  rigidity,  but  the  cylindrical 
top  of  the  funnel  is  not  wired. 

A rubber  band  may  be  stretched  around  the  funnel 
at  the  junction  of  the  cylindrical  and  conical  portions 
to  prevent  waste  by  evaporation  at  this  point.  To 


Fig.  202.  Rain  Gauge. 


insure  accuracy  the  copper  pipe  which  holds  the  glass 
tube  should  be  filled  with  water  before  the  observa- 
tion begins. 

When  the  gauge  is  used  in  a windy  place  it  should 
be  clamped  to  some  fixed  object  by  three  screws  en- 
gaging the  wire  rim  at  the  bottom  of  the  vessel. 


104 


nOMK  MECHANICS  Foil  Ai\lAlMa;KS 


A ]\[I]TALLK^  THEimOMF/rFII. 

A iiier(*TTi'ial  tli(‘rin()in(4(a-  (‘alls  for  ]naTii])iilal ions 
whi(‘li  ar(^  not  Avitliin  lln^  si'oja^  of  tin*  ainatcMii',  but 
rcMjnirc^  the  skill  and  ex])(‘ri(ni(‘(*  of  tin*  i‘(\^ulai‘  niann- 
fac'tnrer.  A nietalli(‘  th(n‘inoni(‘t(a‘,  how(*v(a‘,  is  vcn'v 
easily  made,  and  S(a'V(^s  llu^  ])nr])ose  fnlly  as  av(‘11  as  a 
nierenrial  tliermonuder.  It  ean  1)(‘  imnh^  as  s(‘nsitiv(‘ 
to  the  variations  of  t(an])eratn]‘e  as  may  h(‘  d(^sir(Ml. 

It  is  made  by  ])la(‘ini»’  toi»eih(n‘  a s<i‘i])  of  st(‘(d  and 
one  of  l)rass  (!  inelu^s  loni»,  ] ineh  wid(^  and  3V  iiu'h 
tliiek.  The  ends  of  the  stri])s  ar(^  tiniuMl  for  about  f 
of  an  ineh  at  (^aeh  end  of  their  adja(*ent  fa(‘es,  and 
then  pnt  toi^etlier  and  luxated  tirst  at  one  end  and  them 
at  the  otlier,  so  as  to  solder  them  toj»ether  at  the 
ends. 

The  brass  strip  is  made  about  ^ ineli  ]onf»nr  than 
the  steel  strip,  and  is  bent  over  and  ])erforated  to  re- 
eeive  a silk  thread  as  Avill  be  presently  explained.  Com- 
monly, when  strips  of  steel  and  brass  are  nsed  in  a 
eom])onnd  bar,  they  are  riveted  at  short  intervals,  to 
kee])  them  fi'om  buckling.  In  the  present  case  the 
com])onnd  ])ar  is  provided  Avith  a Avinding  of  soft  Avire 
(No.  *>0)  Avhich  k(^eps  the  strips  close  together.  To  in- 
sure ])(n‘manen(‘y  the  bars  are  drilled  and  riveted  Avith 
a single  rived  at  (^a(‘h  end. 

Th(‘  (‘01111)01111(1  bar  thus  made  is  inserted  in  a round 
lioh^  in  th(^  middh^  of  a hard  Avood  bhx'k  2J  inches 
long,  and  h(4(l  tlnae  by  an  ordinary  AVOod  S(‘reAV  in- 
S(a‘led  in  1h(‘  (*nd  of  lh(‘  blo(‘k  and  (‘lam])ing  the  end  of 
ll)(^  bar.  ''rh(‘  woodem  bIo(‘k  is  S(‘(‘iir(Ml  to  a base  i)ie(‘e, 
1 iii(‘li(*s  s(piai‘(*  and  in(‘h  lhi(‘k,  having  atta(‘h(Ml  to 
jl  a ba(‘k  board  } inch  lhi(‘k,  1 inches  \vid(^,  and  about 


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195 


10  inches  high.  A wire  nail  about  tV  inch  in  diameter 
and  1|  inches  long  is  driven  through  the  back  with  its 
pointed  end  projecting  about  1^  inches.  The  nail  is 
about  I inch  from  the  upper  free  end  of  the  compound 
bar.  A paper  roll  is  formed  upon  another  nail  or  a 
piece  of  wire  a trifle  larger  than  the  one  used  in  the 
construction  of  the  thermometer.  The  strip  of  writ- 
ing paper  used  for  this  roller  should  be  1 inch  wide 
and  about  8 inches  long.  Enough  of  the  paper  is  wound 
to  make  the  roller  ^ inch  in  diameter.  The  paper, 
except  the  first  layer,  is  pasted  as  it  is  rolled,  so  that 
it  forms  a solid  paper  roll  when  it  is  dry. 

This  roll,  when  dry,  is  transferred  to  the  nail  pro- 
jecting from  the  back  piece,  and  a pointer,  or  index, 
about  2|  inches  long  is  cut  from  thick  writing  paper 
and  glued  to  the  end  of  the  roll.  Then  a silk  thread 
is  tied  in  the  eye  in  the  free  end  of  the  compound  bar, 
and  passed  over  the  roller  on  the  nail,  and  wound 
three  times  around  the  roll,  and  it  has  attached  to  it  a 
small  weight.  In  the  present  case  this  weight  consists 
of  a lead  bullet  split  half  open  with  a.  knife,  and 
closed  down  upon  the  thread  by  pliers  or  by  hammer- 
ing. With  every  change  in  temperature  the  compound 
bar  swings,  so  as  to  cause  a movement  of  the  index  by 
the  pulling  or  releasing  of  the  thread  and  the  raising 
or  lowering  of  the  weight. 

The  index  should  be  placed  in  a vertical  position 
when  the  temperature  is  about  70° ; then  the  winding 
of  the  silk  should  be  separated  a little,  and  a small 
drop  of  mucilage  shoiild  be  placed  on  the  middle  con- 
volution of  the  thread  at  the  top  of  the  roller,  so  as 
to  cement  it  to  the  roller  and  prevent  any  change  of 
adjustment. 


19G 


JIOMK  MIOCIly\NI(JS  KOU  AMA'I’KIJUS 


A semicircular  piece  of  bristol  l)oar(],  about  b inches 
in  diameter,  is  temporarily  sui)ported  behind  the  index 
by  a block  ijlued  to  the  back  ])iece.  Tbe  brislol  board 
is  to  form  the  thermometer  scale  and  is  fast(“ned  to 


Fig.  203.  A Metallic  Thermometer. 


11i("  ))]ock  ))y  ta(*lvS  or  ()ili(aA\is(‘,  so  that  it  can  be  re- 
niov'CMl  and  a(‘(airat(‘l y r(‘])Iac(*(l.  A ])(ai(al  mark  is  now 
mad(^  on  the  scab?  at  lh(‘  |)oint  of  tln^  index  whi(*h  indi- 
calc'S  tin*  t(*m|>(a'a<  iir(^  as  shown  by  a nnaaairial  thei‘- 
moni(*l(a*  at  tin*  tinnx  If  it  is  70°,  Ihe  mark  on  the  new 


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197 


scale  represents  this  teniperattire,  and  whenever  the 
index  points  to  this  mark  the  observer  knows  the 
thermometer  is  70°. 

Now  the  thermometer  is  placed  in  a refrigerator 
along  with  a mercnrial  thermometer.  They  are  left  in 
the  refrigerator  for  an  hour,  and  then  a pencil  mark 
is  made  at  the  point  of  the  index.  This  will,  perhaps, 
be  40°.  The  space  between  these  two  marks  is  divided 
into  thirty  even  spaces,  representing  as  many  degrees, 
or  it  may  be  divided  into  fifteen  spaces,  each  of  which 
will  represent  2°.  This  graduated  space  serves  as  a 
guide  for  constructing  the  balance  of  the  scale.  If 
2°  spaces  are  used,  twenty  such  spaces  laid  off  on  the 
leftdiand  side  of  the  scale  will  extend  the  scale  to 
zero.  Twenty  more  such  spaces  will  extend  the  scale 
to  40°  below  zero,  which  is  lower  than  any  temperature 
experienced  in  this  climate.  The  space  between  40° 
and  70°  is  already  graduated,  and  the  space  above  the 
70°  mark  is  graduated  as  described  for  the  lower  end 
of  the  scale.  As  each  line  represents  2°,  10°  would 
be  represented  by  five  lines,  so  that  the  fifth  line  could 
be  extended  beyond  the  other  lines  for  the  sake  of  con- 
venience in  reading.  Figures  from  0°  are  placed  op- 
posite the  long  lines  so  as  to  read  10°,  20°,  30°, 
40°,  and  so  on,  as  in  an  ordinary  thermometer  scale. 

The  amateur  can  refine  this  thermometer  as  mxich  as 
he  pleases.  He  may,  if  he  desires,  place  the  entire  de- 
vice in  a case  and  cover  the  dial  with  a glass,  provided 
he  furnishes  several  apertures  to  enable  the  air  to  cir- 
culate and  thus  keep  the  temperature  the  same  as  that 
of  the  external  air.  The  free  end  of  the  compound  bar 
may  have  a spring  riveted  to  it,  as  shown  in  the  de- 
tached view,  and  an  adjusting  screw  may  be  inserted  in 


IIOMF.  MFCMfAXlC^S  YOU  AMATFTJRS 


\\)9> 

tli(‘  (‘()in])()nii(l  1)^1'  so  as  1o  l)(*ar  a^ainsi  IIk*  s|)riiiiL!:. 
VVitli  tliis  ('oiistiaK'i ion,  ili(‘  silk  11ii'(‘a(l  may  lx*  ti(*<l  in 
a liol(*  in  the  fr(*(*  (*n(l  of  tlie  s])riniL»,  and  tin*  d(*sii‘(*d 
adjustment  may  be  made  by  tnriiin<»  the  S(*r(*\y  om*  way 
or  tlie  otlier. 

I^y  making’  the  (‘om])onnd  l)ar  lon<»(n',  oi*  <liminis]nne: 
tlie  diameter  of  the  (‘ylind(*r  aronnd  \ylii(‘li  tin*  tlir(*ad 
extends,  or  both,  the  sensitiyeness  of  tlie  instrnm(*iit 
may  be  <>reatly  increased. 


SBIPLK  inXHJOSCOPE 

No  instrument  is  recjiiired  to  indicate  a snperabnn- 
ilaiH'e  of  hnmidity  in  the  air.  Eyeryone  know  s tin*  dis- 
comforts of  a moist,  hot  day  in  the  snnimer  without 
recpiiring  a hyj>roscope.  Still,  to  one  scientifically 
inclined  it  is  some  satisfaction  to  know^  the  hygrometric 
state  of  the  air,  and  to  compare  one  day  with  another 
of  the  same  year  or  preyions  years. 

A yery  simple  hygroscope  wiiicli  is  accurate  enough 
for  all  practical  purposes  is  illustrated  by  the  engray- 
ing*.  Its  construction  Ayas  suggested  by  a panel  made 
of  two  pieces  of  Ayood  glued  crossAyise  to  keep  it  straight 
— the  y(*ry  best  arrangement  of  the  grain  for  causing 
it  to  assume  a concayo-coiiAOX  form  under  all  condi- 
lions  of  the  atmosphere  except  that  in  Ayhich  it  Ayas 
gln(*d  tog(*ther.  It  has  a baseboard  4 inches  square 
and  J inch  thi('k,  with  a back  piece  4 inches  Ayide  and 
lo  inch(*s  high  and  ] inch  thi(‘k,  attached  to  one  edge. 
X(*ai‘  1h(*  right-hand  (*dg(*  of  the  base  is  secured  a block 
to  w'hi(‘h  is  attach(*d  a hygros('0])i(‘  strip  made  u])  of 
a longitudinal  ])!(*(*(*  of  any  (*lasti(‘  wood  (such  as  Ayhitc- 
w'ood  j \2  inch(*s  long,  1 inch  wdd(‘  and  tV  iu(di  thi(*k. 


HOME  MECHANICS  FOE  AMATEUES 


199 


and  a transverse  piece  of  wliitewood  of  the  same  thick- 
ness 1 inch  long  and  12  inches  wide,  carefully  glued  to 
it,  so  that  the  grain  of  one  strip  is  at  right  angles  to 
that  of  the  other.  These  strips  of  wood  should  be  well 


Fig.  204.  Hygroscope.  Fig.  205.  Hygroscope  Strip. 

seasoned.  This  coinpoimd  strip  is  secured  to  the  small 
block  on  the  base  of  the  instrument,  and  a piece  of  plain 
cardboard  is  attached  by  two  tacks  to  the  wooden  back 
at  the  center  of  the  board,  leaving  the  ends  of  the  card 
free.  The  concave  side  of  the  strip  should  be  arranged 


200  HOME  MECHANICS  E()]{  AMATKEIiS 


to  face  tho  l(‘ft-liaii(l  sido  of  tlu*  iiisli-uiiuMd,  and  a sliort 
])i(H‘e  of  small  wii^*,  say  No.  24,  or  a li(‘adl(*ss  |)in  should 
1)(‘  iiisertcHl  ])oint  out^^'ard  in  tli(‘  fi‘(‘(‘  (md  of  th(‘  strij) 
to  servo  as  an  index. 

Tli(‘  S(‘ale  is  ('onstrnet(Ml  hy  first  ])la(*ini»;  Hi(‘  instrn- 
nient  niuha'  a Ixdl  i»lass  with  s(n(‘ral  ])i(M‘(‘s  of  w(‘t 
hIottini»  ])a])(a‘  near  l)nt  not  toindiini;  th(‘  sti'i]).  Tli(‘ 
loni»’,  narrow  stri])  do(*s  not  (‘han<>(^  its  l(‘n;L»th,  but  is 
bent  one  way  oi-  tli(‘  otlH*r  by  lli(‘  sw(dlin<»  oi'  slirink- 
ing  of  the  pie(‘e  wliieh  is  ('rosswis(‘.  Tin*  liyi>i'o- 

seo])ie  stri])  will  straij»ht(Mi  out  or  ev(m  eni'V(^  in  tln^ 
oj)])osite  direc'tion  wlum  snl)initt(*d  to  tin*  intbumec^  of 
moisture,  and  after  the  lapse  of  six  or  (4!L»ht  lionrs 
the  glass  is  removed  and  a jxmeil  mark  is  mad(^  on  th(^ 
card  at  the  point  of  the  index,  whi(‘h  will  rej)- 
resent  100  degrees,  or  the  point  of  saturation.  The 
instrument  is  allowed  to  assume  the  normal  position 
by  drying  it  in  the  open  air,  after  which  it  is  again 
placed  under  the  bell  glass  with  a dish  of  calcium  chlo- 
ride and  allowed  to  remain  five  or  six  hours.  The  cal- 
cium chloride  removes  the  moisture  and  causes  the 
cross-grained  side  to  shrink  and  tlins  curve  the  strijj 
considerably.  It  now  indicates  the  maximnm  diwness 
of  the  ail',  and  a mark  is  made  at  the  point  of  the  index, 
indicating  zero.  Tln^  spaces  between  zero  and  satura- 
tion should  now  b(^  divided  into  ten  equal  spaces,  and 
(^ach  si)ac(‘  may  be  subdivided  into  ten  spaces,  each 
r(q)r(*s(mring  om^  d(\gr(Hc 

Th(*s(^  lin(*s  should  b(‘  m^atly  made  with  a drawing 
|)(m.  h]v(*ry  Hmlh  graduation  should  be  extended  a 
litth^  and  nnmb(*r(*d;  th(‘  (*ntii'(^  s('al(^  Ixdng  nnmbercMl 
from  0 to  100,  v.  c.,  0,  10,  20,  :{0,  (dc. 

This  insi  riiimml  is  not  inl(*nd(*d  to  a(‘cnrately  show 


HOME  MECHANICS  FOR  AMATEURS 


201 


the  exact  amount  of  moisture,  as  is  the  case  with  the 
more  elaborate  hygrometers,  but  to  affoi’d  a simple 
means  of  showing  the  ever-varying  state  of  the  air. 

MERCURilAL  BAROMETER 

The  variations  of  atmospheric  pressure  are  shown 
by  the  barometer.  The  pressure  of  the  air  in  round 
numbers  is  15  pounds  per  scpiare  inch ; that  is,  a col- 
umn of  air  1 inch  square,  the  height  of  the  atmosphere 
(which  is  not  positively  known),  weighs  15  pounds, 
and  will  balance  a column  of  water  1 inch  square  and 
34  feet  high,  or  a column  of  mercury  1 square  inch  in 
area  and  30  inches  high. 

A mercurial  barometer  is  here  shown  on  account  of 
facility  of  construction  and  the  acciiracy  of  its  opera- 
tion. To  make  the  simplest  form  of  mercurial  barom- 
eter, a strong  glass  tube  a little  more  than  33  inches 
long  and  about  tV  inch  internal  diameter  is  required. 
It  must  be  sealed  at  one  end,  and  left  open  and  con- 
tracted to  ^ inch  at  the  other.  This  work  is  readily 
done  b}’  a glass  blower.  The  open  end  is  fused  to 
remove  the  sharp  edges.  A small  glass  bottle  is  pro- 
vided, the  body  of  which  is  about  1 inch  internal  diam- 
eter and  1^  inches  high.  The  neck  is  short  and  a 
little  larger  internally  than  the  outside  of  the  tube. 
A board  f inch  thick,  3 inches  wide  and  39  inches  long 
has  a shallow  half-round  groove  to  receive  the  glass 
tube,  and  two  brass  straps  extend  over  the  tube  and 
are  clamped  to  the  board  by  means  of  screws.  Near 
the  bottom  of  the  board  a hole  is  cut  for  the  glass 
bottle  or  cistern,  as  it  is  called ; a small  shelf  is  secured 
by  screws  to  the  back  board,  even  with  the  lower 


202 


HOMK  MKC0IA\M(^S  YOU  A^WTYYU^ 


side  of  tlio  liol(‘  hi  <li(^  board.  A small  bob*  is  made* 
ill  tli(‘  liac'k  lioard  lu^ai'  tli(‘  lo])  to  r(M‘(*iv(*  tlH‘  nail  oi* 
S(‘r(^w  111)011  Avliicli  the  iiistriiiiKmt  lianas. 


Fk;.  20f>.  Scale  and  Indicator.  Fig.  207.  Mercurial  Barometer. 

Of  eonrs(^  all  Uk*  ])arts  will  be  triinl  in  pla(*e  before 
at h*iii |)l i to  fill  tli(‘  tiib(‘  with  iiieriairy. 

"riu*  tiilx^  must  b(^  ])(a'le(‘lly  (di^aiij  and  only  re-dis- 
tilbxl  iiKaaairy  should  b(^  ns(*d.  In  the  bottom  of  the 


TTOirE  JIECHANTCS  foe  AIMATETTES 


203 


j>lass  bottle  is  placed  a laj-er  of  pure  beeswax  iV  incb 
thick.  The  wax  is  made  smooth  and  level  by  meltiiijj; 
it  by  "eiitly  heating  the  glass  bottle  over  an  alcohol  or 
Rnnsen  gas  flame.  When  the  wax  is  cold  the  tilling' 
of  the  tube  with  mercury  may  l)e  proceeded  with.  The 
tube  and  the  mercury  are  first  warmed  by  passing 
them  over  an  alcohol  or  gas  flame ; then  mercury  is 
poured  into  the  tube  through  a small  paper  funnel. 
The  tnbe  should  be  filled  fo  within  ^ inch  of  the 
end  with  mercury.  Then  the  clean,  dry  forefinger  is 
held  over  the  ojien  end  of  the  tube  and  the  tube  is 
placed  in  a horizontal  ])osition  and  tilted  one  way  and 
then  the  other,  to  allow  the  bubl)]e  of  air  to  gather 
up  as  much  as  possible  of  the  air  contained  in  the  tube. 
The  tube  is  then  ])laced  open  end  np  and  entirely  filled 
with  mercury.  It  is  then  invert(‘d  while  it  is  kept 
closed  hj  the  finder.  The  end  of  the  tnbe  is  placed  be- 
low a body  of  mercury  in  a suitable  vessel  and  a little 
of  the  mercury  is  let  ont  so  as  to  produce  a partial 
vacnnm  at  the  top.  Tlien  the  tnbe  is  (‘losed  and  again 
turned  into  a horizontal  position  and  tilted  in  one  way 
and  then  the  other,  and  at  the  same  time  turned  or 
rolled  over  so  as  to  cause  the  bubble  to  gather  up  any 
air  that  may  remain.  The  tube  is  again  inverted  and 
filled,  until  it  is  entirely  full  of  mercury.  The  finger 
is  again  applied,  and  a vacuum  is  produced  by  allow- 
ing a small  amount  of  mercury  to  escape,  when  the 
tube  is  vertical  as  before.  It  is  closed  and  tilted,  allow- 
ing the  bubble  to  again  gather  air.  This  operation  is 
repeated  two  or  three  times.  The  tube  is  finally  in- 
verted and  filled  witli  mercury,  so  as  to  present  a 
convex  surface  above  the  open  end  of  the  tube.  Tlie 
glass  bottle  containing  the  wax  is  placed  over  the 


204  nOMh]  MKC41Ai\M(^S  FOR  AMATVA  UH 


open  end  of  tlie  tube  and  ])r(‘ss(Ml  dowip  (*ansin<»  tb(‘ 
wax  to  inak(^  a i^ood  (‘onta(*t  with  tli(‘  (aid  of  iW  tub(*. 

Tlie  bottle  is  held  fiianly  in  ])laf*(^  by  tla^  lin<»(‘r,  and 
tlie  bottle  and  tlie  tube  may  now  b(^  inv(‘id(Ml  toiL»(‘tli(a', 
and  after  jmttin^*  a little  ineiaairy  in  tli(‘  bottb^,  tb(‘ 
latter  may  be  jilaecMl  on  the  slndf  ])r(‘])ared  for  it,  and 
the  tube  may  be  raised  a litth^j  so  as  to  eb^ai'  its  ojxai 
end  from  the  wax,  and  the  tub(‘  is  fastemxl  in  ])la('(^ 
by  (danipinj>  it  with  the  brass  strijis  and  s(‘rews.  .Morci 
mereury  is  added  to  that  in  the  bottle  so  as  to  make 
the  depth  about  ^ uwh  abov(^  the  low(‘r  end  of  the 
tube.  A quantity  of  clean  cotton  wool  is  plaecxl  in  the 
month  of  the  bottle  around  the  tube  to  exclude  dust, 
at  the  same  time  to  admit  air  fre(dy.  The  barometer 
is  now  finished  Avith  the  exce])tion  of  the  scale. 

A scale  of  inches  f inch  Avide  and  4 inches  long  is 
laid  out  in  the  center  of  a card  24  imdies  Avide  and 
tii  inches  long.  Each  inch  is  divided  into  tenths,  and 
the  divisional  lines  for  the  inches  and  lialf  inches  are 
extended  beyond  the  f inch  limit.  The  beginning  of 
the  scale  is  numbered  27.  The  upper  end  of  the  first 
inch  is  numbered  28,  the  second  inch  is  numbered  29, 
the  third  inch  30,  and  tlie  fourth  inch  31.  The  scale 
is  [ilaced  behind  the  tube  and  the  division  line  corre- 
spomling  Avith  the  line  at  the  top  of  the  mercury  in  a 
standard  bai'ometcu'  is  placed  in  the  same  position  rel- 
atives to  th(^  mercury,  and  fastened  by  small  tacks. 

To  enable^  tlus  obscu-yeu'  to  mark  the  height  of  the  col- 
iimu  of  imuaairy,  so  that  h(‘  may  compare  the  present 
obseu'vation  with  tlu^  ])i‘(‘yious  one,  an  indie-ator  is  pro- 
yieh'd,  which  ('ousists  of  a rod  su])])ort(xl  by  ])osts  at- 
lacli(‘d  to  ili(*  boai'd,  and  a shoil,  sexdion  of  sjiiral 
spring  j)lac(*d  on  tlu^  j'od,  with  the  upiier  extremity 


HOME  MECHANICS  FOR  AMATEURS 


205 


straightened  and  extending  over  the  barometer  tnbe. 
This  end  of  the  wire  is  flattened  by  hammering  to  make 
a more  delicate  index. 

In  a general  way  the  changes  of  the  barometer  are 
given,  but  they  must  be  taken  with  some  allowance. 
High  winds  and  storms  usually  follow  the  sudden  drop 
of  the  mercury.  The  rising  of  the  mercury  generally 
indicates  fair  weather;  the  drop  of  the  mercury  indi- 
cates bad  weather.  The  fall  of  the  mercurv  in  sultrv 
weather  is  followed  by  tliunder ; the  rise  of  the  mercury 
in  winter  indicates  frost.  In  frosty  weather  the  fall 
of  the  mercury  precedes  a thaw,  and  the  rise  is  followed 
bv  snow.  Sudden  changes  in  tlie  barometer  indicate 
similar  changes  in  the  weatlier.  Cpntinned  foul 
weather  may  be  expected  if  the  mercury  falls  slowly; 
on  the  contrary  if  it  rises  slowly  continned  fair  weather 
may  be  looked  for.  Changeable  weather  is  indicated  by 
an  unsettled  barometer. 

It  is  perhaps  unnecessary  to  caution  the  maker  of 
the  barometer  to  conduct  the  various  operations  of 
Ailing  and  adjusting  above  a large  iflatter  or  piece  of 
smooth  paper,  witli  the  edges  turned  up  to  avoid  un- 
necessary waste  of  mercury. 


PART  YI. 

TELESCOPES  AND  MICROSCOPES 

HOW  TO  MAKE  A TELESCOPE 

NO  ONE  can  look  into  the  starry  depths  at 
night  without  a feeling  of  wonder  and  awe, 
nor  is  this  feeling  lessened  when  the  mind 
grapples  the  question  of  space  and  con- 
templates the  awful  abysm  that  separates  ns  from 
even  the  nearest  star,  to  say  nothing  of  the  points 
of  light  faintly  visible  to  the  naked  eye,  nor  of  the 
telescopic  stars  removed  to  such  distances  as  to  be- 
wilder the  mind  and  baffle  the  imagination  in  the 
attempt  to  realize  their  remoteness. 

Who  does  not  desire  to  become  more  familiar  with 
these  distant  bodies  and  to  possess  all  the  knowledge 
that  can  be  obtained  by  observation?  Much  can  be 
done  by  the  unaided  eyes,  and  a great  deal  more  can 
be  accomplished  by  means  of  a telescope  of  very  mod- 
erate proportions  and  power.  An  ordinary  opera  glass 
is  not  to  be  despised,  but  of  course  an  instrument  with 
a larger  objective  and  a longer  focus  is  much  more 
efficient  and  desirable. 

Our  engraving  represents  the  telescope,  its  standard, 
and  the  various  parts,  in  section  and  in  detail.  The  ob- 
ject glass,  A,  shown  in  the  engraving,  is  a meniscus 
lens  2|  inches  in  diameter  and  36  to  38  inches  focus.  It 
is  mounted  in  a wooden  cell,  B,  having  an  internal 
flange  or  fillet  about  -ij  inch  wide,  forming  a true  sup- 
port for  the  lens  and  bearing  against  the  end  of  the 
paper  tube,  D,  which  forms  the  body  of  the  telescope. 

[207] 


208 


IIOMI-:  MKCIlANlCR  FOIJ  AMA'I'EURS 


Tlu“  Ions  is  retained  in  its  cell  by  a flat  stri]),  E,  of  brass 
wbicb  is  sprang-  into  tbe  cell  and  is  pushed  down 
against  tlie  lens.  Tin*  (-(‘II  is  fastian'd  to  tbe  tnbe  by 


Fig.  208.  A Simple  Telescope. 

ooininon  wood  screws,  wlii(*li  pass  tliroiii»’li  tlie  collar 
into  tin*  |)a|)(M‘  foraniiiiL*'  tli(^  tul)(\  It  is  ])crlia])S  needless 
to  sny  (hat  tla^  (*(*II  slioiild  1)(‘  inad(‘  of  soiu(‘  thoroniL»ldy 


HOME  MECHANICS  FOE  AMATEURS  209 


seasoned  hard  wood,  which  is  not  liable  to  atmospheric 
influences.  Hard  maple  answers  a good  purpose,  but 
mahogany  is  to  be  preferred. 

To  protect  the  objective  when  not  in  use  a cap,  F,  of 
tin  or  pasteboard  neatly  covered  with  morocco  or 
velvet  is  fitted  to  the  cell. 

The  paper  tube  of  which  the  telescope  body  is  formed 
is  such  as  is  commonly  used  for  rolling  engravings  for 
mailing.  It  is  3 inches  external  diameter  and  32  inches 
long  (about  4 inches  shorter  than  the  focus  of  the 
objective).  The  exterior  of  the  tube  is  covered  with 
Java  canvas  attached  by  means  of  bookbinder’s  paste 
(flour  paste  with  ghie  added),  and  varnished  when  dry 
with  two  or  three  thin  coats  of  shellac  varnish.  This 
gives  the  tube  an  elegant  and  durable  fluish. 

The  focusing  tube,  G,  which  is  of  brass,  Ir}  inches 
internal  diameter,  and  12  inches  long,  is  guided  by  a 
turned  wooden  piece,  II,  fitted  to  the  end  of  the  jjaste- 
board  tube,  D,  and  held  by  three  or  four  ordinary 
round-headed  wood  screws. 

The  piece,  II,  has  a shoulder,  a,  against  which  the 
end  of  the  pasteboard  tube  abuts,  and  only  about  three- 
quarters  of  an  inch  of  the  piece,  11,  actually  fits  the 
tube,  the  portion  from  b to  c being  tapered  as  indicated 
in  the  engraving,  and  near  the  extreme  inner  end, 
about  3^  inches  from  the  shoulder,  there  are  three 
screws,  d,  used  in  collimating  the  fociising  tube,  G. 

The  bore  of  the  piece,  H,  is  somewhat  larger  than 
the  focusing  tube,  G,  and  is  provided  with  a cloth  lin- 
ing, e,  at  each  end  to  insure  the  smooth  working  of 
the  tube. 

A short  distance  from  the  .shoulder,  a,  a mortise 
about  three-quarters  of  an  inch  square  is  made  through 


210 


IIOMIO  MKCUIANK'S  KOIJ  AMA'I’Kl' l.’S 


tlio  side  of  (lie  tub(‘,  7),  and  (lie  ]iiece,  II,  and  a (rans- 
vei'se  slot,  /,  is  formed  to  receive*  tlie  wood(*n  s]»indl(‘,  I, 
which  is  enlarijed  in  the  niiddh*  to  r(*ceive  the  rnhher 
thimhle,  J,  and  has  on  om*  (*nd  a milled  head  h_v  which 
it  may  he  turned.  The  sjiindle,  I,  is  held  in  place  hy 
concave  pieces,  (},  which  in  turn  are  retaim'd  hy  the 
curved  ])late,  7.*,  attached  to  the  tube,  I),  hy  screws. 
The  rubber  thimhle,  J,  must  he  of  sufficient  diameter  to 
reach  to  and  jiress  upon  the  focusing'  tula*,  and  the 
latter  has  a series  of  transverse  liroovc's  tih'd  in  it. 
This  Avill  insure  sulticient  friction  to  move  tin*  tube, 
G,  in  and  out  when  the  s])indle,  T,  is  tuimed.  This  sim- 
ple device  replaces  the  usual  focusinij  nu-chanism,  and 
is  to  he  preferred  to  a rack  and  pinion,  uidc'ss  the  latter 
he  i^erfectly  made,  and  it  is  certainly  superior  on  the 
score  of  cheapness. 

The  cell,  B,  piece,  H,  and  spindle,  I,  should  he 
blacked  and  polished  on  the  outside,  and  the  cell  should 
he  left  dead  black  on  the  inside.  The  interior  of  the 
tubes  should  also  be  dead  black.  This  surface  may  he 
secured  hy  adding  lampblack  to  a little  very  thin  shel- 
lac varnish,  and  aiDplying  it  to  the  inside  of  the  tube  hy 
means  fif  a swab.  The  focal  lengths  of  the  lenses  of 
the  astronomical  eyepiece  should  he  to  each  other  as 
three  to  one;  the  field  lens,  which  is  nearest  the  object 
glass,  having  the  greatest  diameter  and  the  longest 
focus,  and  the  convex  side  of  each  lens  should  he  turned 
toward  the;  object  glass.  Their  distance  apart  should 
he  one-half  the  sum  of  tlu'ir  focal  lengths.  These  lenses 
are  mounted  in  a wood(*n  cell,  L,  whose  (‘xterior  is 
fitted  to  th(i  focusing  tube,  (J,  and  grooved  circumfer- 
entially to  receive*  a striji  of  cloth,  which  is  glued  in, 
ami  insni'cs  a good  fit.  d’lu*  c(*ll  is  bored  in  different 


HOME  MECHANICS  FOR  AMATEURS 


211 


diameters  to  receive  the  field  lens,  h,  the  diaphragm,  i, 
and  the  eye  lens,  /,  all  of  which  ai’e  held  in  place  against 
the  shoulders  formed  in  the  cell  by  circular  springs  of 
brass,  which  are  sprung  in  as  in  the  case  of  the  object 
glass.  The  eye  aperture  should  be  about  tf  inch,  and 
the  aperture  of  the  diaphragm  should  be  about  the 
same. 

It  is  well  enough  to  make  the  diaphragm  adjustable, 
so  that  it  may  be  moved  back  and  fortli  to  secure  the 
best  position.  It  will  be  found,  however,  that,  if  placed 
just  beyond  the  focus  of  the  eye  lens,  it  will  give  the 
best  resiilts. 

A circular  recess,  /.•,  is  formed  in  the  face  of  the  eye- 
piece to  receive  a sun  glass,  which  is  retained  in  place 
when  in  use,  by  a short  curved  s]U‘ing,  1.  The  sun  glass 
is  simply  a disk  of  very  dark  glass.  It  must,  in  fact, 
be  nearly  opaque;  some  of  the  glass,  known  as  black 
glass,  answers  the  pui'pose  very  well. 

If  but  one  astronomical  ejmpiece  is  made,  probably 
the  most  satisfactory  combination  would  be : Field 
lens,  inches  focal  length ; eye  lens,  inch ; distance 
apart,  1 inch.  It  is  advisable,  however,  to  have  three 
ej'epieces  for  different  purposes — one  of  higher  power 
and  one  of  lower  power  than  the  one  descril)ed. 

In  this  connection,  I will  describe  a terrestrial  eye- 
piece, referring  to  the  sectional  view.  Fig.  209,  al- 
though it  is  of  little  use  to  adapt  such  an  eyepiece  to 
this  instrument  unless  it  is  first  provided  with  an 
achromatic  objective.  It  is  then  a powerful  telescope, 
which  will  enable  one  to  see  well  for  many  miles.  The 
method  of  mounting  the  lenses  described  in  connection 
with  the  astronomical  eyepieces  will  be  followed  here, 
thei’efore  little  more  than  the  diameter  and  focus  of 


213 


iioMK  ]\ii:crjANi(:s  foii  ama'phi’ijs 


tlie  lensos  and  tlioir  distance  apart  need  be  fjiven. 
There  are  fonr  plano-convc'x  lenses,  A',  15',  1)', 

nionnted  in  two  ]>airs  in  Avood(‘n  cells,  E',  E',  litted  to 
the  tnbe,  (}',  Avhicli  in  turn  is  tittcd  lo  th(‘  focnsini^ 
tnbe,  (r.  The  cell,  py,  has  a |-inch  ap(*rtnr(“  for  the  (*y(* 
and  a bead  which  ])roj(‘cts  beyond  the  tnla*,  (}'. 
The  lens.  A',  is  abont  xV  iin-h  in  diaiindi'r  and  1 inch 


Fig.  209.  Details  of  Telescope  and  Terrestrial  Eyepiece. 

focus.  Tli(^  l(Mis,  iVy  is  2 incli  diamotor  and  inch 
focus.  "rii(‘  haiSj  O'y  is  iV  in(‘li  dianictcr,  1 1 inch  focus. 
FIk*  1(*iis,  I)',  is  2 iiK'li  diani(‘i(‘r  and  1 j inch  fo(ais.  Tlie 
})lini(‘  fpc(^  of  i\'  is  I7  in(‘lH‘s  from  tlu^.  ])lanc  face  of 
J>',  and  a stop,  IT,  having  a iV  inch  apertni'e,  is  placed 


HOME  MECHANICS  FOR  AMATEURS 


213 


inches  from  the  face  of  the  lens,  A'.  From  the  plane 
face  of  the  lens,  B',  to  the  plane  side  of  the  lens,  C', 
it  is  3f  inches.  The  distance  between  the  plane  side  of 
the  lens,  C',  and  the  plane  face  of  the  lens,  D',  is 
inches.  At  a distance  of  iV  inch  from  the  face  of  the 
lens,  €',  there  is  a diaphragm,  I',  having  a ^-inch  aper- 
ture. It  will  be  observed  that  the  convex  sides  of  the 
lenses,  C'  D,  are  turned  toward  each  other. 


Fig.  210.  Details  of  Telescope. 

At  the  extreme  inner  end  of  the  tube,  G',  there  is  a 
diaphragm,  K',  of  if  aperture,  which  is  held  in  place 
by  two  circular  springs.  The  interior  surfaces  must 
be  well  blacked  to  prevent  reflection. 


214  llOMI^  MKCniANK^S  KOI?  AMA1M^nM?S 


I liav(^  ('lu^aj)  y(‘i  (‘fficicMil  in(*lli()(ls  of  holding 

the  l(‘iiS(‘S.  If  (l(‘sir(Ml  Ok*  i'(‘a(l(*r  may,  of  ooinsc*,  make* 
flu*  moTnitiiiiL»s  of  l)rass,  and  lit  Ok*  insti'iim(*iit  ii])  a(*- 
('oi'diiii;‘  to  Ids  tast(*  and  ability. 

TIk*  arrani>(*nK*nt  of  tin*  vaidons  ])ar<>s  is  (d(*ai'ly 
sliown  in  tlio  se(4ional  view,  No.  kb'iL»\  20!),  and  Ok* 
foousin<»*  d(*vi(‘e  is  sliown  in  No.  2,  V\<^.  210. 

In  r(*i>ard  to  the  mattnr  of  (‘olliniation  1 liav(*  found 
tliat  by  (*nttin<>’  off  tin*  (*nds  of  Ok*  ])a])(*r  tnb(*  tiaily  in 
a lathe,  the  ('(*11,  1>,  and  tin*  ])i(*('(*,  11,  will  b(*  nK*as- 
nrably  true.  To  determine  wheth(*r  tin*  fo('nsini>  tnlx*, 
(x,  and  ('(*11,  B,  are  axially  in  lim*,  a truly  ('lit  eardboard 
disk  Avith  a pin  hole  exa('tly  in  the  ('enter,  may  be 
placed  in  the  e(*ll,  B.  A similar  disk  may  also  lie  placed 
in  each  end  of  the  focnsin<»‘  tube,  (x. 

Now,  by  adjnstino’  the  pi(*ce,  II,  by  means  of  the 
three  screws,  (/,  the  three  pin  holes  in  the  disks  may  be 
readily  brought  upon  the  same  axial  line;  then,  if  the 
lenses  have  been  carefully  centered  by  the  maniifac- 
tnrer,  the  telescope  Avill  be  found  sufficiently  well 
('ollimated.  If,  however,  it  is  desired  to  ascertain 
whether  the  lens  is  trnlv  centered,  it  mav  be  turned  in 
its  cell,  Avhile  the  telescope  is  in  a fixed  position,  and 
directed  at  some  immovable  object.  If  the  image  moves 
as  th(*  l(*ns  is  turned,  it  shows  that  the  work  has  been 
('ar(*l(*ssly  dom*. 

If  OK*r(*  ar(*  doubts  as  to  vdiether  the  axis  of  the 
obj(*('tiv(*  ('oiiK'id(*s  with  the  axis  of  the  tube,  the  tube 
laay  b(*  snp[)()rt(‘(l  in  V-shap(*d  supports  adapted  to  the 
tridy  tKT‘iK*d  (*n(ls.  Then  by  placing  a candle  at  some 
(listaiK'(*  from  IIk*  fa('(*  of  tin*  l(*ns,  and  turning  the 
tube  in  ils  V sn|)ports,  at  IIk*  saiiK*  liiiK*  viewing  the 
i'(*ll(*('tioii  of  tin*  ('aiidb*  in  the  l(*ns,  it  will  at  once  be 


HOME  MECHANICS  FOR  AMATEURS 


215 


known  by  the  movement  of  the  reflection  that  the  cell 
requires  adjustment  to  render  the  axis  of  the  objective 
and  that  of  the  tube  coincident. 

With  a telescope  of  this  description  a large  number 
of  celestial  objects  may  be  examined  with  great  satis- 
faction. The  Moon  furnishes  an  unending  source  of  de- 
light, showing,  as  it  does,  a face  that  is  ever  changing 
throughout  the  lunar  month.  Jupiter  may  be  coming 
into  good  position  and  affords  an  interesting  study 
of  which  one  does  not  soon  tire.  The  telescope  de- 
scribed will  show  the  satellites  in  their  varying  posi- 
tions from  night  to  night.  It  will  show  the  dark  band 
across  the  face  of  the  planet,  and  will  afford  a realizing 
sense  of  the  magnitude  of  this  great  body. 

Saturn  may  be  in  a good  position  for  observation, 
and  his  ring  may  be  clearly  seen.  The  meniscus  lens 
will  show  a little  color,  and  its  definition  will  be  quite 
defective  Avhen  directed  to  such  bright  objects  as  the 
Moon,  Jupiter,  Saturn,  Mars,  or  Venus  with  the 
full  aperture,  therefore  the  aperture  should  be  re- 
duced by  a diaphragm  of  cardboard.  A little  experi- 
ment will  determine  the  best  sized  aperture.  For  nebu- 
Im,  star  groups,  and  double  stars,  the  full  aperture 
should  be  used.  The  great  nebula  of  Orion  is  an  inter- 
esting object;  many  of  the  star  groups  are  very  pleas- 
ing, the  Pleiades  for  instance.  The  sun  also,  when  the 
spots  are  visible,  is  a satisfactory  object  for  this  instru- 
ment. Of  course,  the  sun  glass  will  be  applied  before 
the  observer  attempts  to  view  the  Sun,  otherwise  the 
eye  may  be  injured  or  destroyed.  It  may  be  that  some 
reader  of  this  article  may  have  a double  or  plano-con- 
vex lens  of  long  focus,  which  he  might  desire  to  press 
into  the  service.  Either  of  these  may  be  used,  but  the 


2i(; 


HOME  TMKCIIANICS  EOi;  AMAI'KUKS 


iiuMiiscus  is  1)(><H‘i‘.  If  a .nood  j(»1»  is  made  of  flu*  nioinif- 
iiijUS  it  will  ii(»t  be  loiijn  befoiM*  Hk*  iiienisciis,  or  Hi<? 
piano  or  double  eonv(“x  lens  will  b(‘  snp])lan1ed  b.v  a 
^'ood  aebroniatie  objectivi*,  which  will  increase*  tine 
efiliciency  of  the  instrninent  many  fold.  Such  a hms 
is  not  very  (*x])ensive.  It  may  he  procni'esl  from  almost 
any  optician. 

As  to  the  telescope  stand  little  m-ed  he  said,  as  its 
construction  is  so  ch'arly  shown  in  the  (“ivi>ravin;L’’.  I 
will  say,  howev(*r,  in  the  h(‘|i> inning',  that  there*  is  ne» 
dange*r  of  i*ettin;>-  it  teeee  seeliel.  If  it  is  ve*ry  e-Inmsy  it  is 
no  matter.  If  it  is  sle*neler  it  will  he*  like*  a “re*e*el  shaken 
bj’  the  wind,'’  eenly  “men-e  se),”  as  e*ve*ry  trenieer  has  the* 
henetit  of  the  maj>nifyin,i>’  i)e)we*rs  eef  the  tele*se-e)pe  anel  is 
amplified  to  a wonderful  exte*nt. 

There  are  undonht(*elly  hette*r  stands  than  the*  erne 
represented,  hnt  it  is  easily  constrncte*el  anel  answers  an 
excellent  piirpeese.  I*T*om  the  gronnel  tee  the  top  of 
the  hexagonal  hnh,  AI,  it  is  fonr  feet.  Thr(*e  of  the  al- 
ternate sides  of  the  hnh  are  wider  than  the  internieeliate 
ones,  to  receive  the  wronght  iron  hinges  by  wliieh  the 
legs  are  attached.  To  attach  the  hinges,  the  pin  is  first 
driven  ont;  one-half  of  the  hinge  is  then  attached  to 
the  leg,  and  the  other  half  to  the  hnh,  AI,  when  the  pin 
is  replaced. 

No.  1,  Fig.  209,  is  a top  view  of  the  hnh  and  the  npper 
poi  tion  of  the  l(*gs.  No.  4,  h'ig.  210,  is  a vertical  section 
on  1h(*  line,  //,  (/,  in  Fig.  209.  A 1-^-inch  hole  is  bored 
Hii*(mgh  the  hnh  to  rec(*iv(*  the  standard,  N,  which  sup- 
ports tin*  t(*l(*scop(*  and  is  clami)(*d  at  any  desired 
h(*iglit  by  I In*  flinnd)  scr(*w,  m.  To  i)r(*v(*nt  marring  the 
stamlai'd  a pi(*c(*  of  sob*  l(*alh(*r  is  int(*rposed  between 
tin*  scr(*w  and  standard.  An  arm,  n,  is  hing(*d  to  each 


HOME  MECHANICS  FOR  AMATEURS  217 


of  the  legs  and  folds  down  upon  the  standard,  so  as 
to  spring  the  legs  outwardly,  and  thus  render  the  stand 
very  rigid.  The  lower  ends  of  the  legs  terminate  in 
spikes,  and  a strap  is  attached  to  one  of  the  legs  to 
fasten  them  all  together  when  the  instrument  is  not 
in  use. 

The  upper  end  of  the  standard,  N,  is  reduced  in 
size,  and  made  slightly  conical  for  receiving  a socket, 
O,  to  the  upper  end  of  which  is  jointed  an  arm  attached 
to  the  V-shaped  trough,  P,  in  which  the  telescope  is 
secured  by  straps.  The  form  of  the  joint  is  shown  in 
Fig.  210,  which  is  a vertical  transverse  section  taken 
through  the  socket,  O,  trough,  P,  and  body  of  the  tele- 
scope. A strong  bolt,  o,  forms  the  pivot  of  the  joint 
between  the  socket,  O,  and  trough,  P,  and  is  provided 
with  a wing  nut  by  which  it  may  be  tightened.  The 
surfaces  of  the  joint  as  well  as  the  upper  end  of  the 
standard  should  be  coated  with  black  lead  to  insure 
smooth  working.  A post  set  firmly  in  the  ground, 
while  it  cannot  be  moved  from  place  to  place,  has  the 
advantage  of  being  rigid,  and  forms  one  of  the  best  of 
cheap  stands.  A fixture  screwed  in  the  window  casing 
of  a south  window,  and  another  attached  to  a north 
window,  afford  solid  supports  for  the  instrument,  and 
have  the  additional  advantage  of  permitting  the  ob- 
server to  remain  under  cover. 


218  IIOMI':  MKCIIANJCS  FOR  AMATEURS 


THE  .MI('i;,()S(’()FE 

Tlie  man  who  has  passed  hovliood  witliout  kiiowini; 
somethiuj;'  of  wliat  is  revealed  hy  the  mieroseojK*,  lias 
missed  one  of  (lie  pl(‘asui(>s  of  life,  and  has  failed  to 
look  into  one  of  tlie  most  inteiestinj;’  and  pi'otitahle 
studies  oiien  to  the  sec'ker  after  knowl(Hl<;e. 

Frohahlj  the  best  form  of  sim])le  mieroseojie  foi*  tlie 
beginner  is  a Doublet,  of  whieb  three  forms  are  shown 
in  the  engi'aviug.  If  this  eannot  be  had,  a cloth  tester, 
or  a jeweler’s  eyeglass,  will  show  niueli  which  the  eye 
cannot  see  distinctly.  The  doublet  consists  of  two 
plano-convex  lenses  mounted  in  a short  tube  with  their 
convex  surfaces  facing  (‘ach  other,  and  separated  by  a 
distance  equal  to  one-half  the  sum  of  their  focal 
lengths. 

The  habit  of  using  the  lens  creates  the  habit  of  ob- 
servation, and  this  rapidly  increases  one’s  fund  of 
general  information. 

The  doublet  is  convenient  and  inexpensive.  Its 
power,  however,  is  fixed.  If  a different  power  is  re- 
quired another  doublet  will  be  needed.  Probably 
three-fourths  inch  is  the  most  useful  focus. 

Better  for  real  work  is  the  microscope  shown  in 
Fig.  212.  It  has  a glass  plate  on  which  to  place 
the  object  to  be  examined,  and  is  provided  with  a 
ndrror  to  reflect  light  from  below  up  through  trans- 
])arent  or  translucent  objects.  The  arm  which  carries 
the  lens  swings  so  as  to  bring  the  lens  over  any  part  of 
1h<‘  ])late  and  sli])S  r<‘adily  up  or  down  to  bring  any  part 
of  (h(M)bjeet  into  focus.  The  lenses  are  doublets.  They 
may  be  had  of  1i  inch,  1 in.,  -1  in.,  and  | in.  focus. 
Probably  (he,  il  im  h and  | inch  will  prove  the  most 


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serviceable.  The  wooden  base  is  beveled  at  either  end 
to  form  rests  for  the  hands  in  manipulating'  the  objects 
and  lens. 

In  a slide  under  the  base  is  placed  a metal  plate 
enameled  black  on  one  side  and  white  on  the  other. 
This  is  to  be  placed  on  the  glass  stage  when  opaque 
objects  are  tinder  examination. 

This  instrument  will  not  take  the  place  of  a com- 
pound microscope,  but  it  answers  very  well  when  only 


Fig.  211.  Dissecting  Microscope. 

a low  power  is  needed.  If  the  user  develops  a taste 
for  microscopy  and  purchases  a regular  microscope,  the 
dissecting  microscope  will  still  be  of  value  to  him  in 
the  preparation  and  preliminary  examination  of  objects 
to  be  examined  Ity  the  higher  power  of  the  compound 
microscope,  so  that  the  purchase  of  a dissecting  micro- 
scope is  only  introductory  to  the  study  of  microscopy. 

Interesting  objects  for  the  dissecting  microscope  are 
plant  hairs  on  the  back  of  the  leaf  of  the  Deutzia 


^20  HOME  ]\ri-]Cir ANTES  T-'OIT  A:\IA'l’KrUS 


.Cfrncilis,  or  spimon,  and  many  otlior  loav(“s  with  sur- 
faces ronfili  to  the  toncli.  ^Tany  of  the  mints  and  fi^- 
worts  have  hairs  Avond(*rfnlly  InaTiclied.  T’olhm, 
seeds,  Willi's  and  antennae  of  hntterflies,  mosses,  s])ore- 
cases  of  ferns,  insects,  jiarasites,  hairs,  featliers,  min- 
erals, crystals, — all  are  interestin';;-  and  instructive. 
The  formation  of  ciystals  on  the  j;lass  staj^e  is  very  in- 
teresting-. 

Drop  a small  (quantity  of  a solution  of  alum,  com- 
mon salt,  sulphate  of  copper,  or  other  chemical  salt, 
sal  ammoniac  for  exam])le,  u])on  the  glass  stage  and 
allow  it  to  evaporate  while  the  operation  is  watched 
through  the  lens.  For  best  results  spread  the  drop 
of  solution  with  the  edge  of  a paper  cutter  or  card  into 
a thin  film.  A little  practice  will  enable  one  to  make 
a very  uniform  film  in  which  the  crystals  form  very 
beautifully. 

Of  course  the  glasses  must  be  perfectly  clean.  Per- 
fect cleanliness  is  absolutely  essential  in  every  part 
of  microscopic  work.  Dust  especially  is  the  worst  foe 
of  the  microscopist.  It  is  well  nigh  impossible  to  be 
entirely  rid  of  it,  and  every  mote  which  remains  is 
magnified  by  the  higher  powei’s  into  a beam. 

A l)ee  furnishes  a good  object  for  dissection  and 
preparation.  The  wings  and  the  sting  are  especially 
interesting.  The  wings  are  provided  with  hooks  de- 
signed to  engage  a rib  on  the  other  half.  It  is  stated 
that  no  human  being  has  ever  been  able  to  fasten  the 
wings  together.  The  feet  and  respiratory  apparatus 
are  also  interesting. 

l>y  a little  labor  one  may  dissect  from  a flower  or  in- 
sect iiit(‘rior  parts  of  great  interest.  Indeed,  it  is  by 
dissection  that  most  objects  are  prepared  for  perma- 


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221 


uent  preservation  and  nse.  Tlie  tools  for  tins  work  are 
few  and  simple,  and  altliongli  those  sold  by  dealers 
are  to  be  preferred,  yet  one  may  prepare  for  himself 
such  substitutes  as  will  enable  him  to  do  really  good 


Fig.  212.  A Practical  Microscope. 

work.  Our  space  does  not  allow  much  to  be  said  upon 
this  point.  The  indispensable  articles  are  needles 
and  knives.  Dissecting  needles  are  simply  sewing 
needles  set  in  handles.  Even  a splinter  of  wood  or 


222 


IIOM  K M K(MIA\  K^S  Foil  AMAIM^FIIS 


AV()()(l(‘n  ])(‘iili()l(l(M'  answ(‘rs  all  ])in‘])()S(*s  of  a liaadh^, 
and  th(^  (‘V(‘  (aid  of  a ihmmIU*  may  lx*  ])nsli(*d  into  it  so 
as  to  lx*  fiianly  S(*t  in  its  s(*at.  S(*v(*i'al  siz(*s  of  n(*(*dl(*s 
slionld  lx*  nionnt(*d  r(*ady  for  ns(*.  A small  ])oint(*d 
blade*  of  a ]x*nknif(*  will  answ(*i'  for  cnttini*’.  A v(*ry 
suitable  knife  may  be  made*  by  <;rindin<;  tin*  (*nd  of  a 
ne(*dle  to  an  ed,<»e  and  sliar]x*nin<>  it  on  a stom*.  Tli(*s(* 
tools  tlioni>b  sim])le,  are  s(‘rvi(‘(*abl(*. 

To  diss(*(‘t  a t1ow(*r,  for  (*xam])l(*,  ])la(‘(*  it  n]X)n  tln^ 
stai»(*  of  the  microsco])(*  and  bi'ini»'  into  forns  with  the 
lens  so  that  it  is  distimdly  visible*.  At  tirst  ns(*  the 
lens  of  loni»(*st  forns.  Th(*n  take*  a nee*dle*  in  e*ae‘h  lianel 
anel  ope*n  the  tlowe*r,  while  yon  le)e)lv  inte)  it.  ()bse*rve* 
its  petals,  their  eole)rs,  markings  anel  hairs,  if  any  are 
present,  its  stamens,  their  sha])es  anel  pe)lle*n,  its  seH*d 
ve*ssel  anel  any  peeadiarity.  ^tany  an  exepiisite  view 
into  Nature's  me)st  beantifnl  ree‘esse*s  is  te)  be  hael  in 
this  way.  So  beantifnl  are  many  tle)wers  that  e)ne  feeds 
it  to  be  almost  a profanation  e)f  a sacreel  shrine  to  ex- 
pleme  fnrthen\  Rnt  still  the  nnle)edvino'  of  the  shrine 
may  elisede)se  more  profonnel  mysteries,  so  we  proceed  to 
cut  with  one  of  onr  tinv  knives  across  the  seeel  vessel 
which  e)ccnpie*s  the  cemter  of  the  flower.  Notice  the 
symme*try  e)f  its  arrani»ement,  perhaps  in  three  sections, 
else  in  four  or  five*;  sometimes  as  many  as  ten  rows  of 
se(*ds  may  be  found.  It  is  a very  interestino-  point  to 
study  lh(*  arraniL»(*ment  and  phu'e  of  attachment  of  the 
s(*(*ds  in  lh(*  v(*ss(*I.  This  mode  of  working*  is  the  mode 
ns(*d  by  all  botanists  in  th(*ir  ])r(*liniinarv  study  of  a 
plant.  An  (*ntonioloi^ist  stndi(*s  an  ins(*(‘t  in  the  same 
AN'ay. 

Afl(*f*  lli(*  limits  of  vision  with  tin*  loniL»  bxmsed 
h*ns  is  reacli(‘d,  a liii;li(‘r  po\\’(‘r  is  tak(*n  and  tlu*  s(*arch 


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is  continued  to  the  shortest  focus  the  student  may  have. 
All  of  the  “coarse  anatomy”  of  an  object  is  studied 
by  means  of  the  dissecting  microscope.  The  com- 
pound microscope  inverts  the  view  of  an  object  so  that 
a motion  to  the  right  seems  to  be  toward  the  left,  and 
towards,  seems  to  be  from  one.  It  is  very  difficult  to 
become  accustomed  to  this  inversion  in  dissecting,  and 
for  that  reason  the  compound  microscope  is  rarely  used 
even  by  the  most  expert.  Then,  too,  its  field  of  view 
is  small,  and  high  powers  are  not  needed  in  dissecting. 

The  beginner  is  earnestly  advised  to  study  all  sorts 
of  minute  things  which  he  may  find,  since  discoveries, 
surprises  and  most  sublime  views  into  the  hidden 
things  of  Nature  await  him  at  every  turn.  A most 
useful  book  for  this  line  of  work  is  “Common  Objects 
for  the  Microscope,”  which  the  student  is  advised  to 
buv. 

But  with  even  the  highest  skill  there  is  a limit  to  the 
use  of  simple  magnifying  glasses.  The  desire  to  know 
what  lies  beyond  must  be  gratified  in  other  ways.  A 
compound  microscope  is  the  only  instrument  which 
will  meet  this  condition  and  disclose  all  that  can  be 
seen  by  lenses.  This  consists  of  two  lenses,  one  at  each 
end  of  a tube,  which  is  in  two  parts,  one  sliding  within 
the  other.  The  lens  nearest  the  object  is  the  objective 
and  is  really  a very  fine  simple  microscope  in  itself. 
The  upper  lens,  the  eyepiece,  increases  the  magnifica- 
tion of  the  objective  and  enables  the  eye  when  in  the 
proper  position  to  take  in  at  once  the  entire  picture 
produced  by  the  instrument,  and  to  study  it  in  detail. 

The  particular  instrument  shown  in  Fig.  211, 
although  very  plain  and  simple,  is  exceedingly  well 
made,  and  very  useful.  It  will  receive  the  standard 


224 


IIOAIK  MKCMIANMCS  VOU  AMA4M^:rRS 


()l)j(M*tivos  and  oyei)i(M‘es.  Tt  lias  a \(^vy  sinootli  rack 
motion,  wliicdi  admits  of  v(a*v  fim^  adjiistimmt.  Tin* 
mai>iiifi('ation  of  a comjionnd  mi(*ros(‘0])e  is  vai'icMl  by 
nsin<»‘  obje(‘tiv(^s  of  diffVi'ent  fo(‘al  b‘ni»'tlis,  (*y(‘])i(*(‘(‘s  of 
different  ])ow(M's,  and  by  elianain^  tli(‘  bmi^tli  of  tlie 
tnlie.  Tliis  mi('ros(‘0])(‘  is  nsiially  jii'ovided  witli  a lialf 
ineli  objective  wliicdi  may  lie  se])ai‘at(Hl  to  form  a om? 
and  a lialf  in(*li  objective  also,  and  an  iiK'li  and  a half 
<\ve])ie(‘e. 

If  one  wishes  to  put  more  money  into  the  micro- 
scope he  will  next  need  a one-half  inch  eyepiece  and  a 
one-fourth  iiu'h  objec'tive.  Witli  thes(‘  he  will  have  six 
degrees  of  magnitication  at  his  (‘omniand,  varying  from 
25  diameters  to  about  400  diameters.  By  diame- 
ters is  meant  the  number  of  times  bi'oader  an  object 
a])pears.  This  is  the  usual  mode  of  stating  magnifica- 
tion. The  numb(‘r  of  times  an  oliject  is  magnified  is 
found  by  multiplying  the  diameter  by  itself.  Thus, 
if  a seed  is  magnified  fifty  diameters  it  is  made  to  ap- 
pear twenty-five  hundred  times  its  real  size. 

A micros(‘ope  of  the  value  of  this  one  should  be 
handled  with  extreme  care.  There  are  certain  simple 
points  to  be  observed  in  the  use  and  care  of  fine  glasses. 
Never  touch  th.em  with  the  bare  fingers.  It  greases 
them  and  injures  their  transparency.  Wipe  them  only 
with  a very  soft  clean  cloth,  or  bit  of  chamois  skin. 
Th(^  glass  of  whi(*h  tln^  lenses  are  made  is  very  soft  and 
(‘asily  sci'at(*hed.  The  finest  dust  may  be  composed 
of  hard  grit,  whi(‘h  will  leave  its  mark  upon  the  lens  if 
nibb(*d  across  it.  It  is  well  to  blow  the  dust  off  be- 
foi'c^  wiping  th(^  hms.  Lensc^s  a7*(‘  (^asily  broken  if 
dr'opp(‘d.  Th(‘  iriost  (‘ommon  a(‘(‘id(ait  is  the  di'opping 
of  I Ik*  obj(*ctivm  while  scrcwving  it  into  its  ])la(‘e  or  re- 


HOME  MECHANICS  EOH  AMATEUIIS 


225 


moving  it.  Even  with  care  this  sometimes  happens. 
There  is  but  one  way  of  screwing  or  unscrewing  the 
lens  from  the  tube  which  is  certain  to  prevent  accident. 
Take  the  lens  between  the  first  and  second  fingers  of 
the  left  hand,  just  as  one  would  a cork  or  a lead  pencil. 
Now  hold  it  in  the  position  to  be  screwed  into  the  tube 
and  turn  it  in  Avholly  by  the  right  hand.  Proceed  in 
the  same  manner  in  unscrewing  the  lens.  No  accident 
can  happen. 

With  this  microscope  fitted  with  the  half  inch  separa- 
ble objective  and  the  one  and  a half  inch  eyepiece  an 
exhaustless  field  of  study  and  delight  is  opened  to  its 
possessor. 


■ 


PART  YII. 

ELECTRICITY 

A PKACTICAL  PRIMARY  BATTERY 

Every  amateur  who  delights  in  “making  things” 
dabbles  more  or  less  with  electricity.  Most  of 
these  are  so  situated  that  they  have  no  access 
to  the  large  sources  of  supply  of  the  electric  cur- 
rent, such  as  lighting  stations  can  furnish,  and  if  they 
would  do  any  real  work  must  make  their  own  genera- 
tors and  apparatus.  It  is  to  the  assistance  of  such 
that  the  present  section  is  devoted. 

The  battery,  represented  by  Fig.  213,  can  be  made  at 
a minimum  cost,  and  when  made  will  give  a maximum 
of  output.  The  materials  to  be  purchased  are  glass 
jars,  porous  cups,  carbons,  zincs,  burrs,  screws,  bind- 
ing posts  and  some  sheet  copper. 

All  the  pieces  for  the  cell  come  ready  for  use,  except 
the  carbons,  which  are  peculiar  to  the  special  form  of 
cell.  As  the  cut  shows,  there  is  a ring  of  carbons  to  be 
placed  in  the  glass  jar  and  to  fit  in  the  jar  as  closely  as 
may  be  without  exerting  pressure  upon  the  jar.  Six 
plates  of  carbon  are  required  for  each  ring.  Each 
plate  has  two  holes  of  a size  to  lit  the  screws.  The 
holes  may  be  made  most  easily  by  awls  and  reamers, 
such  as  are  to  be  found  in  a set  of  tools  in  an  awl 
handle.  A little  patience  and  experience  will  enable 
any  one  to  make  the  holes  neatly.  Carbon  is  verj^  hard 
and  will  wear  a drill  very  fast.  Hence,  it  is  better  not 
to  attempt  drilling  holes  in  a carbon  plate.  Of  course 
the  holes  should  be  eqiially  spaced,  if  the  appearance 
of  the  finished  work  is  to  be  considered. 

[227] 


Tli(^  (*()])])(‘r  should  lx*  about  1-.‘^>2(1  of  an  iiudi  in  thick- 
n(*ss  and  about  § wide*.  II  (*an  be*  bon^iil  of 

this  width,  or  ont  by  tin*  d(*al(*r  or  by  a sinilb  with  lai‘<»(* 
sboai's.  A stri])  must  lx*  lx*nl  into  a six-sid(*d  rinjL»  of 
siudi  size  that  when  tin*  eai'bons  an*  fast(*ned  to  it  tin* 
whole  will  slide*  snugly  into  I In*  i»lass  jar.  It  will  lx* 
better  after  oiu*  stri])  has  b(*(*n  titl(*d  |o  its  ])la('(*  to 
straighten  it  out  and  use  it  as  a pattern,  or  template*. 


Pig.  213.  A Practical  Primary  Battery. 


by  wliicli  to  drill  the  holes  in  the  rest  of  the  copper 
strips.  They  will  then  be  all  alike  and  interchange- 
able*. A t(‘inplate  shonld  also  be  nsed  for  making  the 
lioles  in  the*  carbons,  tlioiigh  all  holes  may  be  reamed  a 
liltb*  on  one  side*  eei*  the*  eether  te>  allow  the  screw  te)  pass 
1 l)i*e»iigli.  If  I lie*  \\e»)-ke*r  has  ne>  means  eif  tapping  a 
llii-e'ael  feir  (lie*  se*i'e*w,  he*  sliemlel  bay  nuts  feer  the  screws 
alsei.  H’lie*  lie)le*s  in  I lie*  e-eijipe*!*  s(ri]is  may  b(^  ]mne*hed 
wil  li  a nail  pnne-li,  if  enie*  has  iiei  nie*ans  e)f  elrilling  them. 


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229 


For  punching  holes  in  this  way  the  end  of  a stick  of 
hard  wood  should  be  used  as  a bed  to  rest  the  copper 
upon  wlien  punched.  The  strip  of  copper  which  leads 
up  out  to  the  binding  post  may  be  riveted  to  the  ring, 
or  one  end  of  the  ring  may  be  left  long  enough  to  bend 
up  a couple  of  inches  above  the  top  of  the  jar.  The  car- 
bons should  be  long  enough  to  reach  above  the  jar  so 
that  the  metal  parts  shall  not  touch  the  glass.  In  this 
battery  the  fluid  employed  will  corrode  metals  very  rap- 
idly. To  prevent  the  fluid  from  creeping  up  through 
the  pores  of  the  carbon  and  reaching  the  copper,  the 
ends  of  the  carbons  should  be  dipped  in  hot  melted 
paraffine  and  saturated  by  it  before  clamping  them  to 
the  copper  ring. 

The  binding  posts  may  be  of  any  available  form  ex- 
cept those  with  wood  screws.  A machine  screw  is  nec- 
essary because  the  l>inding  post  is  to  be  clamped  to  the 
copper  strip  by  it.  When  these  parts  are  screwed  to- 
gether the  battery  is  ready  to  be  assembled. 

Nothing  has  been  said  about  the  sizes  of  jars  and  the 
rest,  since  the  cell  may  be  made  of  a size  to  fit  any  jar 
into  which  the  porous  cup  and  carbons  Avill  go.  Hound 
porous  cups  may  be  had  from  inches  up  to  5 inches 
in  outside  diameter,  and  round  glass  jars  may  be  had 
from  2i  inches  up  to  7 inches  in  inside  diameter.  There 
is  thus  ample  range  of  size  for  any  one  to  consult  both 
the  depth  of  his  pocketbook  and  tbe  quantity  of  current 
which  he  Avishes  the  battery  to  giA^e.  This  is  a point 
not  understood  by  many  amateurs.  The  voltage  Avhicli 
a cell  gives  is  determined  by  the  kind  of  chemicals  used 
in  it  and  not  by  the  quantities  of  chemicals  consumed. 
The  current  in  amperes,  Avhich,  the  voltage  being  fixed, 
the  cell  will  give,  and  the  work  it  can  therefore  do,  are 


2:50 


llOiMK  MKCIIANICS  FOll  A^IATKVWH 


l)y  tli(‘  (|naiility  of  clKMiiicals  (‘oiishhkmI  l)y 
the  (‘ell  ill  its  ac'lioii.  It  may  Ix^  statixl  as  a fair  av(‘r- 
aiL»e  rc^siilt  that  oih^  ])oiiii(1  of  ziiie  will  i»i\(‘  :52()  ainjx^re 
hours  ill  a (*(^11  such  as  this. 

Carbon  jilates  (‘an  be  had  in  a ,i^T(‘at  vanety  of  sizi^s 
and  sha])(\s.  Tin*  b(‘st  way  is  for  tlu^  oiu*  (‘ont(mi])latinii^ 
inakini>'  the  batt(n'y  to  writ(^  to  a d(^al(n‘  in  (de(‘tri(‘al 
sni)])li(^s  and  ask  for  a (‘atal()i»n(^j  Avhi(‘h  h(^  will  be  f;lad 
to  furnish.  All  tlu^  ])arts  (‘an  tlnni  b(‘  s(*l(X‘ted  of  ])ro])er 
jiroportion  to  ea(‘h  other,  so  that  tluw  will  <»()  toi;ether. 
Either  the  Daniell,  bottle  or  Enller  zin(‘  should  be  (^(xl. 
The  ent  shows  the  Daniell  zinc.  It  is  a e,ood  form  be- 
(‘anse  of  the  lari»e  snrfa(‘e  exposed  to  the  aetion  of  the 
tlnid. 

The  best  solution  for  this  cell  is  the  (‘hroniie  acid 
fluid.  It  should  be  made  by  weight,  taking  chro- 
mic acid  18  parts,  water  60  parts,  snlphnric  acid,  con- 
centrated, 9 parts.  A pint  of  water  may  be  taken  as  a 
pound,  and  a pint  of  the  snlphnric  acid  as  1.8  pounds. 
The  chromic  acid  is  a solid  and  can  be  most  easily 
weighed  directly.  Put  the  chromic  acid  into  the  water. 
It  dissolves  readily.  Then  pour  the  snlphnric  acid  into 
the  mixture  very  slowly,  a little  at  a time,  stirring  it 
in  thoroughly,  else  a disagreeable  accident  may  be  had 
from  the  heat  produced.  It  is  considered  by  many  that 
this  solution  is  improved  by  adding  1 part  of  chlorate 
of  j)()tash.  When  it  is  cold  it  is  ready  for  use. 

The  zinc  in  all  cells  of  this  character  must  be  amal- 
gaiiiat(Hl;  that  is,  (‘()at(xl  with  mercury.  This  may  be 
doiK^  (lir(X‘tly  by  dipping  tlu^  zinc  into  the  solution  for 
a short  tinn^  and  tlum  i‘nbbing  m(n‘cnrv  ni)()n  it,  or,  bet- 
1(*]*,  by  initting  an  onm‘(^  of  m(‘r(‘nry  into  the  bottom  of 
(‘a(‘h  ])oi‘ons  (‘iip.  Another  way  is  to  add  to  the  solu- 


HOME  MECHANICS  FOR  AMATEURS 


231 


tion  in  each  porous  cup,  as  much  bisulphate  of  mer- 
cury as  will  lie  on  a quarter  of  a dollar.  The  zincs 
will  then  be  amalgamated  directly  from  the  solution. 

The  cell  may  be  set  up  in  various  ways  with  only 
slight  differences  in  the  resulting  current,  durability 
and  constancy  of  action.  We  will  give  four  modes  of 
arranging  the  cells : 

First — Fill  the  glass  jar  to  within  an  inch  of  the  top 
and  the  porous  cup  to  the  same  level  with  the  solution 
described  above. 

Second — Fill  the  porous  cup  with  a mixture  of  water 
10  parts  and  sulphuric  acid  1 part,  and  the  glass  jar 
with  the  chromic  acid  mixture  given  above. 

Third — Fill  the  glass  jar  with  the  chromic  acid  solu- 
tion and  the  porous  cup  with  water  to  which  table  salt 
has  been  added  at  the  rate  of  4 oz.  to  the  pint.  Sul- 
phate of  zinc  may  be  used  in  place  of  salt,  6 oz.  to  the 
pint. 

Ftour — Fill  the  glass  jar  with  chromic  acid  solution 
and  the  porous  cup  with  clear  water.  This  will  start 
slower  than  any  of  the  other  modes  of  filling,  but  will 
work,  because  enough  of  the  chromic  acid  solution 
passes  through  the  pores  of  the  cup  to  act  upon  the 
zinc. 

The  adaptedness  of  this  cell  for  many  uses  is  shown 
by  the  fact  that  it  can  be  arranged  as  a one  fluid  cell 
also.  Removing  the  porous  cup  hang  the  zinc  in  the 
center  of  the  glass  jar  by  means  of  a board  cover  of  the 
jar  through  which  a hole  is  made  to  receive  the  end  of 
the  zinc.  The  fluid  used  will  be  the  chromic  acid  solu- 
tion. The  zinc  must  be  fully  amalgamated  before  put- 
ting it  into  service,  and  the  bisulphate  of  mercury 
should  be  used  to  maintain  the  zinc  in  condition.  In 


232 


HOME  MECHANICS  EOl?  AMATEHES 


Hiis  form  flu*  coll  _i>ivos  its  stroii<rost  current,  but  will 
only  last  about  half  as  lou"'. 

Whcuovor  this  coll  is  to  Ix'  out  of  use  the  zinc  should 
be  rouiovod  from  the  ll(|ui(l.  The  porous  cup  should 
be  taken  out  and  sot  in  a dish  of  the  sauu*  solution 
as  it  coiitaius.  In  this  way  all  waste  of  the  chemi- 
cals is  prevented. 

The  battery,  as  doscrilxal,  is  one  of  the  stroupjest  and 
most  I’eliable  primary  batteries.  AVith  its  strongest 
current  it  readily  heats  tine  iron  and  ])latiunm  wires. 
With  the  porous  cup  it  is  ada])ted  to  drive  motors,  fans, 
and  excite  electromagnets.  A large'  battery  will  light 
small  incandescent  lamps.  Eight  or  ten  cells,  holding 
two  quarts  each,  will  drive  the  motor  of  Hcientific 
American  Snpplcmcnt,  No.  041,  to  full  power,  and  run 
a sewing  machine  or  turn  a small  lathe,  or  do  any  other 
equal  work.  The  expense  of  maintenance  is  not  great. 
The  liquid  when  it  becomes  green  is  exhausted  and 
must  be  replaced  by  fresh  solution.  The  zincs  can  be 
used  till  they  are  entirely  dissolved.  This  battery  is 
not  a toy,  but  a serviceable  piece  of  working  apparatus. 


ELECTRIC  LIGHTINCx  FOR  AMATEURS 

It  is  now  possible  for  any  one  to  procure  small  incan- 
descent lamps  from  the  Edison  Lamp  Co.  and  from 
most  dealers  in  electrical  goods.  These  little  lamps 
can  be  o[X‘rated  (piite  successfully  by  means  of  easily 
constructed  batteries.  It  is,  of  course,  a little  trouble- 
some, and  the  (*x]x*use  of  the  electric  light  produced  in 
this  way  is  somewhat  grc'ater  than  other  lights,  but 
amat(‘urs  can  d(‘riv('  a gr<‘at  deal  of  satisfaction  from 
Hiese  (‘xix'riux'iits  in  eh'ctric  lighting. 

Tin;  battejy  may  be  made  at  home,  from  materials 


HOME  MECHANICS  FOR  AMATEURS 


233 


that  may  be  purchased  from  the  manufacturers  of  the 
lamps  or  from  any  dealer  in  electrical  supplies.  Each 
cell  of  battery  consists  of  two  plates  of  carbon  2 in. 
wide,  4^  in.  long,  and  | in.  thick,  one  zinc  plate  2 
in.  wide,  4 in.  long,  and  i in.  thick,  two  strips  of  wood 
4 in.  wide,  4 thick,  and  4 in.  long,  two  strong 
rubber  bands,  and  an  ordinary"  tumbler. 

The  zinc  is  amalgamated  by  dipping  it  in  dilute  sul- 


phuric acid  (acid  one  part,  water  twelve  parts),  then 
sprinkling  on  a few  small  drops  of  mercury,  rubbing  it 
about  with  a swab  formed  of  a piece  of  cotton  cloth 
tied  around  the  end  of  a stick.  Every  portion  of  the 
surface  of  the  zinc  should  be  covered  with  mercury.  If 
the  amalgamation  is  perfect,  it  need  not  be  repeated. 

The  carbon  plates  before  use  should  each  be  heated 


IIOMK  MKCMfAXICS  KOI?  AMM^KKIJS 


2:U 

a(  one  end  and  salnrat(‘d  wiOi  ])arariin(‘  for  a dislaina* 
of  1:1  in.  from  tlu^  n])i)(‘r  (*nd  (and  no  inoi^*)  to  ])!*(*- 
V(mt  tlu^  solution  fr'oin  as(‘(mdin<i  tln^  ])lat(‘  ))y  (‘a])illar- 
ity.  Tills  is  ae(‘oni])lisli(*<l  liy  In^atinin  lli(‘  (*nd  of  tin* 
plate  over  a lam])  and  a])])lyini»'  a ])i(*e(‘  of  ])ai'anin(^  or 
a ])araffine  (-andle  until  it  is  till(Ml.  No  fi‘(‘(^  ])araf11n(‘ 
should  be  allow(‘d  to  rcmiain  on  tin*  snrfae(‘  of  tln^  eai‘- 
1)011,  as  it  will  int(n'f(n'(^  with  niakini»‘  a i>()od  (*l(M*trieal 
eonne(*tion  with  the  plate. 


Fig.  215.  A Tumbler  Battery. 


The  zinc  plate  is  jilaeed  between  the  two  wooden 
stri])s.  The  (‘arbon  plates  are  placed  outside  of  the 
strips  and  held  by  the  two  rubber  bauds,  as  shown  in 
Fio.  214. 

The  coiiuectiou  between  the  carbon  plates  and  the 
wire  leading'  away  from  tln^  cai'bon  ])ole  is  made  by  a 
donbl(*d  strip,  e,  of  (‘opper,  tlu^  (mds  of  Avhi(4i  are  in- 
S(n't(Ml  b(4  w'(*(m  lh(‘  woochm  stri])s  and  the  (*arbon  ])lates. 
In  a similar  way  a (*op|)(*r  strip,  />,  is  inserted  betw^een 


HOME  MECHANICS  FOR  AMATEURS  235 

f 

the  zinc  plate  and  one  of  the  wooden  strips.  The 
tumbler  forming  the  battery  jar  should  be  deep  enough 
to  allow  the  wooden  strips  to  rest  upon  its  rim,  so  as 
to  support  the  plates  a short  distance  from  the  bottom 
of  the  tumbler. 

The  ordinary  bichromate  of  potash  solution  is  used 
in  the  battery.  It  is  prepared  by  making  a saturated 


solution  of  common  bichromate  of  potash  in  warm 
water ; then,  after  cooling,  adding  very  slowly  a quan- 
tity of  common  sulphuric  acid,  equal  to  about  one-fifth 
of  the  bulk  of  the  bichromate  solution.  It  is  advisable 
to  add  to  the  solution  a very  small  quantity  of  bisul- 
phate of  mercury,  say  one-eighth  ounce  to  the  quart  of 
solution,  to  maintain  the  amalgamation  of  the  zinc- 


230  HOME  MECHANICS  EOT?  A^rATECRS 


Tli(‘  salts  known  as  tlio  (\  k ( \ 1>a<l(‘ry  (‘oin])onn(l  ar(‘ 
oxrellont  and  V(nw  com (‘iiicnit  for  ns(^  in  l)att(*ri(*s  of 
this  (‘lass.  It  is  only  n(‘(‘(‘ssary  to  dissoHa^  this  conn 
pound  in  wat(n‘  to  form  th(‘  (‘Xf'itinjj^  solution. 

This  mat(n‘ial  is  sold  in  tin  (‘ans  (‘ontainini^  two  or 
thiTG  pounds.  It  absoT'hs  moisture^  i‘a])idly,  so  that 
wlum  it  is  to  Ix^  ns(‘d  in  sinall  (|nantiti(‘S  it  shonld  1)(‘ 
transf(n‘r(Ml  to  a sto])])Gr(Ml  ,i>lass  jar. 

It  is,  ])erha])S,  ikmxIIc^ss  to  say  that  ^r(‘at  (‘an^  shonld 


Fig.  217.  A Series  of  Connected  Lamps. 


1)0  Gxerciscxl  in  handlinj]^  the  solution,  as  it  is  poisonous 
and  (h^structive  to  clothing,  carpets,  etc.  The  same  re- 
mark  a})])li(^s  to  the  battery  compound. 

One  c(dl  of  ibis  battery  should  be  allowed  for  each 
candh^  j)ower  of  the  lamp.  The  zinc  of  one  cell  should 
b(i  coniKX'bxl  with  tli(^  cai'bon  of  the  lu^xt,  khg.  215.  The 
batt(a‘y  may  lx*  ari‘ang(*d  as  a ])lunger.  Directions  for 
making  a,  batl(*i‘y  of  Ihis  kind  w(*r(*  giy(*n  on  page  11(5, 
of  volnnui  57,  of  IIk*  >SV‘/cn//7/r;  A ntrrwan. 


HOME  MECHANICS  FOR  AMATEURS 


237 


In  Fig.  216  is  shown  a convenient  bracket  for  sup- 
porting small  electric  lamps.  It  consists  of  two  curved 
wires  attached  to  a small  piece  of  board  by  means  of 
screws,  which  also  serve  as  binding  screws  for  attaching 
the  wires.  The  lamp  is  suspended  from  eyes  formed  in 
the  ends  of  the  wires.  Tliis  device  may  be  used  as  a 
standard,  as  shown  at  1,  as  a hanger,  as  shown  at  2,  or 
as  a bracket,  as  at  3. 

In  Fig.  217  is  shown  a series  of  three  small  lamps 
connected  with  three  cells  of  battery. 

The  lamps  in  this  case  are  connected  in  parallel  or 
multiple  are,  i.  e.,  one  binding  screw  of  each  lamp  is 
connected  with  one  wire  from  the  battery.  The  other 
binding  screws  of  the  lamps  are  all  connected  with  the 
remaining  pole  of  the  battery. 

Copper  wire.  No.  18  or  larger,  should  be  used  for 
making  the  connections.  The  battery  will  run  continu- 
ously with  a single  charge  of  the  solution  for  about 
three  hours.  Should  the  solution  become  warm  and 
give  off  hydrogen,  the  zinc  should  be  reamalgamated  at 
the  points  where  it  is  violently  attacked. 


THE  ELECTRIC  CHIME. 

To  secure  practice  in  mechanics  or  in  electrical  work, 
the  amateur  may  as  well  construct  something  for 
actual  use.  A very  useful  and  pleasing  electro-me- 
chanical device  is  an  electric  chime  to  be  used  as  a 
door  bell  or  call  bell,  or  in  connection  with  a clock.  It 
serves  its  purpose  as  a call  and  gives  an  ever-changing 
series  of  harmonic  notes. 

The  first  step  toward  the  construction  of  this  device 
is  to  purchase  the  toy  known  as  the  tubophone,  and 


238  llOMK  MI^XnrANK^S  FOR  AMA1M^:URS 

sele(‘t  tlire("  of  tli(  tubes  wliieh  pro(lii(*(»  a (*lior(l,  or  if 
the  maker  ])ref(‘rs  it,  lie  may  Imy  a jiicM-e  of  maiulrf^ 
drawn  brass  tnliinij;*,  f in(*li  (‘xternal  diaimdca',  with 
walls  sV  in(‘b  tlii(*k,  and  (*nt  off  tlircn^  |)i(H*(‘s  r(^s])e(*tively 
7f,  8f,  and  b|  inebes  in  l(miL>;tli ; (nu'li  of  tbesc^  should  b(^ 
laid  upon  two  short  jiieees  of  soft  woolen  eord,  with 


th(^  cord  tonehinf*  at  nodal  points,  that  is,  at  exactly 
oiK^  (piarter  of  the  lenf»th  from  the  end.  Arranoed  in 
this  way  tlie  tulx^s  ^iv(‘  out  a clear  note  when  struck 
with  a small  wood(*n  malhh.  ]>y  com])arin<>  these  notes 
with  1hos(*  of  a piano  oi‘  otlnu'  musi(*al  instrument,  the 
tulx^s  may  Ix^  tum‘d.  Tli(‘  iiitch  is  raised  by  shortening 


Fig.  218.  Electric  Chime. 


HOME  MECHANICS  FOE  AMATEUES 


239 


the  tube,  but  as  there  is  no  practical  way  of  lowering 
the  pitch  after  the  tube  has  once  been  shortened,  it 
would  be  advisable  to  cut  the  tubes  a little  longer 
than  the  measurements  given.  A baseboard  having  a 
short  standard  is  provided,  and  to  the  upper  portion  of 
the  standard  is  secured  a board  into  Avhich  are  driven 
three  pairs  of  wire  nails,  the  nails  in  each  pair  corre- 
sponding in  position  with  the  nodes  of  one  of  the  tubes. 
The  tubes  are  suspended  from  these  nails  b}"  soft 
cords  passing  around  the  tubes  at  the  nodes  or  points 
of  no  vibration,  leaving  the  tubes  free  to  vibrate  at  the 
center  and  at  the  ends. 

Now  it  remains  to  constriict  the  electro-mechanical 
device  for  striking  the  tiibes.  To  the  baseboard  are 
secured  the  angled  ends  of  three  strips  of  spring  brass, 
A inch  wide  and  gV  inch  thick,  which  extend  above 
the  tubes  and  carry  small  wooden  mallets  in  position  to 
strike  the  middle  portion  of  each  tnbe.  The  mallets  are 
secured  to  the  springs  by  means  of  ordinary  wmod 
screws  passing  through  the  springs  into  the  mallets. 

Behind  the  springs,  at  or  near  their  mid-length,  is 
placed  a diagonal  strip  of  wood,  having  secured  to  its 
outer  edge  a strip  of  felt  or  chamois  skin.  The  spring 
strikes  this  piece  and  allows  the  mallet  to  strike  the 
tube  and  spring  back  without  jarriug.  Behind  the 
springs  is  supported  a small  shaft  on  which  is  placed 
a wooden  cylinder  about  1 inch  in  diameter  and  2^ 
inches  long.  In  the  cylinder  and  opposite  the  springs 
are  inserted  wire  nails,  arranged  to  strike  short  in- 
clined strips  riveted  to  the  springs.  The  nails  are 
placed  so  that  they  will  strike  the  inclined  strips  in 
different  orders;  for  example:  1,  2,  3 ; 3,  2,  1 ; 2,  3,  1 ; 
1,  3,  2. 


240  ][()MI':  MECHANICS  FOl!  A:\I ATHUItS 


A toy  (“l(“cti‘ic  motor  liaviiij;  a tlir(‘(‘-))ol(‘  armature* 
is  list’d  for  tiiriiiu<i:  tlie  cyliiidcr,  ami  two  clock  wlu’cls 
and  a pinion  are*  emplovt’d  for  ri’ducinn  tlie  siioed.  A 
worm  is  jilaccd  on  tlu’  armatiiro  sliaft  of  the  motor, 
Avliich  (*n<ja,i>(’s  tlu*  first  of  the  clock  wheels.  This  worm 
may  lie  cut  in  a lathe,  hut  if  this  is  inconvenient,  a 
Avire  may  be  Avoiind  sfiirally  around  tlu’  armature  shaft 
and  solderc’d.  It  Avill,  of  course*,  he  ne*e-e*ssary  tei  Avinel 
the  spiral  so  that  it  Avill  fit  the  teeth  eef  the  chick  Avheel, 
and  the  surplus  seileler  shemhl  he  scra])e*el  fi-emi  the  Avire 
to  eliminish  friction.  The  motor  is  preivieled  Avith  hinel- 
ini*'  posts  to  receive  the  hatte’rv  Avii-e*s.  One  eir  tAvei  cells 
of  dry  battery  Avill  run  the  chime.  The*  chime  is  nseel 
in  place  of  an  eirelinary  call  eir  deieer  he*ll,  or  it  may  he 
used  in  connectiem  Avith  a clock,  as  sheiwn,  for  making 
calls  at  certain  hours. 

The  iiiish  button  shoAvn  in  the  sectional  A’ieAV  is  made 
to  close  the  circuit  Avhen  the  chime  is  nseel  in  place  of  a 
call  hell  or  door  hell.  The  hnttou  is  readily  made  by 
boring  a small  block.  A,  of  hard  Avood  in  two  diameters 
to  receive  the  head  and  back  of  the  pearl  collar  button, 
the  back  of  Avhicli  is  held  in  place  by  the  apertured 
piece  of  A'eneering  secured  to  the  face  of  the  block  by 
small  screws,  AA’hile  tlie  head  of  the  button  rests  on  a 
cnrA'ed  brass  spi'ing,  C,  secured  in  a slot  in  the  back  of 
the  block.  A,  by  a scroAV.  The  outer  end  of  the  spring 
proj(*cts  b(*yond  the  side  of  the  block  to  receive  one  of 
the  circuit  wiri’s.  This  slot  is  filled  beloAV  the  spring 
Avilh  insulating  mat(*rial,  and  a brass  plate,  D,  is 
secured  to  tin*  back  of  tin*  block,  .1,  and  has  upon  one 
edg(*  an  ap(*i( iir(*d  (*ar  for  r(*c(*iving  the  other  circuit 
Aviri*.  Tin*  plalc*,  />,  is  secnri’d  lo  tin*  back  of  the  block 
by  small  scri’ws.  Tin*  fr(*(‘  end  of  the  spring,  C,  is 


HOME  MECHx\XICS  FOR  AMATEURS 


241 


curved  over  to  a point  near  the  brass  plate,  D,  so  that 
when  the  spring  is  depressed  by  pressing  the  button. 
B,  it  will  touch  the  plate  and  close  the  circuit. 

The  annexed  diagram  shows  an  appliance  which  en- 
ables the  chime  to  be  used  in  connection  with  a clock. 


In  front  of  the  dial  of  an  ordinary  clock  are  secured 
the  rings,  A,  B,  made  of  inch  square  brass  wire. 
The  supports  are  of  insulating  material,  and  the  rings 
are  concentric  with  the  arbor  carrying  tlie  hands.  The 
hands  are  bent  outwardly  to  permit  of  extending  over 
the  rings  without  touching  them,  and  to  insure  the 
hands  against  electrical  contact  with  the  rings  a thin 
short  sleeve  of  paper  is  slipped  over  each  hand  near  the 
free  end.  Each  ring  has  several  small  radial  holes 
bored  in  it  to  receive  the  brass  nails,  the  heads  of  which 
project  sufficiently  bej’ond  the  front  surface  of  the 
rings  to  enable  the  hands  to  touch  them  as  they  pass. 

The  circmit  wires  connecting  the  battery  and  the 
chime  are  connected  one  with  the  outer  ring.  A,  the 
other  with  one  of  the  springs  of  the  cut-out  switch 
shown  in  the  opening  formed  by  the  breaking  away  of 
the  dial.  The  other  spring  is  connected  with  the  inner 
ring,  B.  The  springs  are  insulated  from  each  other. 

On  the  sleeve  which  carries  the  hour  hand  is  mounted 
the  crossed  slotted  cam,  C,  also  shown  detached  in  the 


242 


llOMI^]  MECHANICS  EOJI  A.MATEUl^S 


lar|L>er  figure.  In  tli(‘  slot  of  tliis  (‘am  is  a boat-shajxMl 
follower,  which  sliders  easily  in  the  slot  and  is  longcn* 
than  the  width  of  tlu^  slot,  so  that  it  can,  in  following 


Fug.  219.  Chime  with  Clock  connection. 

1h(^  slot,  1ak(^  th(‘  inmn*  and  oiitcn*  portions  of  the  slot 
in  alt(n‘nat ion.  Tlu^  followin'  is  j)i voted  to  the  angled 
l(W(*r,  (/,  which  is  juisIkmI  by  ilu^  (‘am  Ixdwaxm  the  par- 
all(‘l  springs  and  w ithdrawn  from  them  in  alternation 


HOME  MECHANICS  FOR  AMATEURS 


243 


once  in  12  hours.  The  object  of  this  arrangement  is 
to  cut  out  the  chime  at  night  and  put  it  in  circuit  in  the 
daytime.  The  cam,  C,  and  the  angled  lever,  a,  are 
insulated  from  the  clock  movement. 

A switch,  D,  is  provided  for  throwing  the  device  out 
of  action  at  anv  time. 

It  will  be  seen  that  the  hour  hand  must  come  into 
contact  with  the  nail  on  the  inner  circle  and  the  minute 
hand  must  touch  the  nail  in  the  outer  circle  to  com- 
plete the  circuit,  and  cause  the  chime  to  sound.  The 
duration  of  the  chiming  is  limited  by  the  time  the 
miniite  hand  is  in  contact  with  the  nail.  The  clock 
when  arranged  as  here  shown  sets  off  the  chime  at  8 
o’clock,  12  o’clock  and  5 o’clock.  It  is  now  about  to 
ring  the  chime  for  12  o’clock. 


HOME-MADE  ELECTRIC  NIGHT  LAMP 

A very  simple  device,  which  will  produce  a temporary 
light  of  one-half  of  one  candle-power,  is  shown  in  the 
illustration.  It  will  be  found  convenient  for  observing 
the  time  at  night,  or  for  momentarily  lighting  a closet 
or  an  area  where  the  light  of  a candle  or  an  oil  lamp 
would  be  objectionable. 

The  miniature  electric  lamp,  and  the  dry  batteries 
used  for  lighting  it,  can  be  purchased  almost  anywhere, 
and  the  labor  of  putting  these  things  together,  with  a 
switch  and  suitable  connections,  is  very  slight  indeed. 
A one-half  candle  lamp  requiring  1.58  amperes  at  2.5 
volts  is  the  first  requisite;  then  two  cells  of  dry  battery, 
giving  a current  with  a pressure  of  about  3 volts  will 
be  needed,  and  last  of  all  a small  packing  box,  that  will 
just  receive  the  batteries,  should  be  selected.  If  a 


344  HOME  MECHANICS  FOR  AT\rA1MajRS 


lain])  of  liii>liei*  yoltaj^o  is  ('liosoii,  laorc^  (‘(*lls  of  l)atIory 
Avill  l)(‘  ii(‘(mI(‘(1.  a 4-volt,  lain])  will  IlircM^  (‘(4Is 

of  battery.  A little  mor(Mi<»lit  will  scxaircMl  willi  this 


Fig.  221.  Battery  Box,  cover  removed. 


Fk;.  222.  Temporary  Light. 


roiiibinal  ion,  bill  il  is  nol  (l(‘sirabl(Ho  iinax^ase  tlienum- 
b('r  of  ((‘lIs  b(*yon(l  lliis,  as  lln*  apparatus  Ixx'oines  at 
once*  loo  bulky  and  loo  (‘x jaaisi V(‘.  Tli(‘  b(‘st  ('oinbiiia- 


245 


HOME  MECHANICS  FOR  AMATEURS 

tion  is  the  one-half  caudle  lamp  wih  two  cells  of  bat- 
tery. After  the  lamp  is  procured  it  should  be  tested  mo- 
meutarily  by  means  of  two  cells  of  dry  battery,  con- 
nected in  series.  If  the  lamp  is  properly  lighted,  a 
packing  box  which  receives  the  batteries  easily  is  se- 


FiCx.  223.  Diagram  of  Circuit. 


lected,  and  two  small  brass  hooks,  f g,  are  straightened 
and  screwed  into  the  box  near  the  top.  Small  copper 
wires  are  placed  in  electric  contact  with  the  hooks,  f g, 
as  shown  in  the  diagram.  At  the  top  of  the  box  is 
placed  a switch,  consisting  of  a piece  of  spring  brass  3 
inches  long  and  | inch  wide  held  in  place  by  a pivotal 
screw,  c,  passing  through  a central  hole  in  the  spring 
into  the  box. 

In  one  of  the  views  the  lamp  is  represented  as  being 
supported  by  a hollow  wooden  column  in  front  of  a 
clock.  In  this  case  one  of  the  lamp  wires  is  incased  in 
a very  small  rubber  tube,  to  insure  insulation;  other- 
wise the  construction  is  similar  to  that  described. 

Two  cells  of  dry  battery  will  light  the  lamp  occa- 
sionally for  a long  time,  if  used  only  an  instant  each 
time;  but  if  the  lamp  is  used  continuously,  it  runs  the 
battery  down,  so  that  it  will  require  frequent  renewal. 

The  wire  from  the  brass  hook,  f,  is  placed  in  electrical 


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contact  Avitli  tliis  screw,  c,  an<l  two  brass  screws,  h c, 
are  inserted  in  the  top  of  the  box,  to  serve  as  contact 
points  for  tli(“  switcli.  1du“S(‘  sci'ews  are  connected  to- 
gether and  with  tlie  zinc  ])(»!(“  of  tlie  cell,  o',  by  a wire. 
The  carbon  ])ole  of  the  cell  is  coniu'cled  (‘lectrically 
with  the  hook,  //.  The  liooks  are  curved  downwai'diy 
and  the  terminals  of  the  lamp,  a,  are  wound  three  or 
four  times  around  the  ends  of  the  liooks,  f </,  respec- 
tiveh",  so  as  to  support  the  laniji  above  and  in  front  of 
the  face  of  the  watch,  hanging  upon  the  hook,  project- 
ing from  the  front  of  the  box. 

The  longer  arm  of  the  switch  is  turned  uji  to  form 
a thumh  piece,  and  is  held  normally  out  of  contact 
with  the  screw,  h.  Hy  pressing  the  end  of  the  switch 
doAvu  into  contact  with  the  screw,  h,  an  electrical  con- 
tact is  formed  which  lights  the  lamp.  By  turning  the 
switch  on  its  pivotal  screw,  c,  it  is  brought  into  contact 
with  the  screw,  c,  thus  forming  an  electrical  contact, 
which  is  prolonged  until  the  switch,  is  returned  to  its 
original  position.  The  movement  of  the  switch  is 
limited  by  the  screws,  d d. 

AN  ELECTRICAL  CABINET 

An  electrical  cabinet  is  an  assemblage  of  articles 
which  may  he  combined  in  various  ways  to  produce 
pieces  of  apparatus.  By  these  a large  number  of  ex- 
jieriments  are  made  accessible  to  the  amateur  at  com- 
jiaratively  slight  expense. 

In  Fig.  224  sectional  drawings  of  the  essential  parts 
are  shown,  drawn  v(“ry  nearly  on  a third  scale.  A are  2 
coils,  Avound  Avith  8 layers  of  No.  20,  single  cotton  cov- 
ered magn<‘t  Avir(‘,  both  Ix'ing  Avouud  in  the  same  direc- 


HOME  MECHANICS  FOR  AMATEURS  24^ 


tion.  B,  the  cores  and  yoke  of  an  electromagnet,  the 
cores  of  f inch  soft  iron  bar.  C,  the  frame  for  support- 
ing the  electromagnet  when  used  as  the  field  coils  of  a 
dynamo  or  motor  as  in  Fig.  237.  D,  a wooden  stand, 
turned  in  a lathe,  to  be  used  as  a support  for  the  com- 


Fig.  224.  General  View  of  Parts. 


J1 


pass  E,  to  form  a galvanometer,  as  in  Fig.  229.  F,  a 
permanent  horse  shoe  magnet.  G,  soft  iron  wires. 
H,  strips  of  copper.  K,  frames  for  telegraph  sounders. 

By  the  aid  of  the  Figures  for  the  several  experiments 
the  practical  amateur  will  have  little  difficulty  in  see- 


248  HOME  ]\IECTIANICS  FOE  A:\IATEUES 


ills'  iiififlc-  put  tosotlicr.  Tlie  poritm- 

neiit  inas'net  and  tlio  oonpiass  can  1)(‘  jmrcliascd  to  hot- 
ter advantaso.  Tlio  rest  can  ho  made  witli  a lathe 
and  tools.  Some  No.  28  spring  brass  wire  will  he 
needed  for  the  springs  shown  on  the  telegraph  sounder 


Fig.  225. 

Effect  of  Iron  on  a Magnet.  Fig.  226.  Decomposition  of  Water. 

at  the  left,  and  some  No.  18  spring  brass  wire  to  be 
Avonnd  into  a close  spiral  a little  less  than  a half  inch 
in  diameter,  and  cut  up  into  pieces  of  about  3 turns 
each  to  be  used  as  connectors  in  place  of  binding  posts. 

In  describing  the  several  experiments  such  addi- 
tional instruction  will  be  given  as  the  case  may  seem 
to  reipiire. 

The  action  of  iron  on  a magnet  is  shown  in  Fig.  225. 
Present  the  end  of  an  iron  rod  to  the  compass.  The 
needh*  is  drawn  towards  the  iron  and  swings  till  it 
points  directly  towards  it.  The  magnet  P may  be  used 
for  this  exi>eriment.  The  north  or  marked  end  of  the 
magnet  rejxds  the  north  end  of  the  needle  and  attracts 
its  south  end.  As  we  say,  like  poles  repel,  unlike  at- 
tract. Th(*  brass  and  glass  cannot  stop  the  attraction. 
Paper,  wood,  anything  excejd  iron,  may  be  interposed 


HOME  MECHANICS  FOR  AMATEURS 


249 


between  the  magnet  and  the  needle  without  destroy- 
ing the  attraction  and  repulsion. 

The  decomposition  of  water  into  two  gases,  oxygen 
and  hydrogen,  by  electricity  is  a very  interesting  ex- 
periment. For  its  best  exhibition  platinum  is  required, 
but  as  this  is  a very  expensive  metal  a method  is  given 
by  which  one  gas  can  be  produced.  Fig.  226  gives  the 
arrangement  of  the  apparatus.  The  light  and  heavy 
parallel  lines  indicate  cells  of  battery.  Two  at  least 
are  required.  A good  form  of  cell  is  represented  in 
Fig.  229.  The  glass  is  a common  tumbler.  Two  plates 
of  battery  carbon  and  one  of  zinc  are  clamped  together 
by  two  bolts  Avhich  pass  through  the  four  strips  of 
wood.  Strips  of  sheet  copper  or  brass,  d and  e,  are 
included  between  the  strips;  d is  cut  long  enough  to 


Fig.  227.  Galvanometer. 


Pig.  228.  Electroplating. 


connect  with  both  carbon  plates.  Two  of  the  spirals 
described  above  are  pushed  on  these  strips  to  receive 
the  copper  wires  used  in  forming  the  circuits.  This 
sort  of  connector  is  nearly  as  good  as  a regular  binding 
post  and  costs  a mere  trifle. 


250 


HOME  MECHANICS  FOK  AMATEUES 


The  fluid  for  the  cells  Is  made  by  dissolving  in  cold 
water  as  much  bichromate  of  soda  as  the  water  will 
take  up,  and  addin"’  slowly  and  with  constant  stirrin" 
one-tenth  of  the  volume  of  sulphuric  acid.  The  plates 
should  only  remain  in  the  solution  while  they  are  in 
actual  use. 


The  tumbler  shown  in  Fig.  226  is  to  be  filled  with 
water  and  a little  sulphuric  acid  added.  Lacking  the 
acid,  vinegar  may  be  used  in  its  stead. 

^Cith  tw'o  cells  fitie  bubbles  of  hydrogen  gas  come  off 
slowly  from  the  copper  which  is  attached  to  the  wire 
leading  from  th(“  zinc  of  .the  battery  and  rise  to  the 
surface.  The  o.xygen  combines  with  the  copper  and 
do(‘S  mtt  appear  as  a gas  at  all.  If  platinum  were  used 


HOME  MECHANICS  FOR  AMATEURS 


251 


for  the  other  strip  oxygen  would  be  given  off  from  its 
surface,  since  oxygen  does  not  combine  with  platinum 
under  these  conditions.  This  most  interesting  experi- 
ment was  first  performed  by  Sir  Humphry  Davy  many 
years  ago. 

Fig.  227  shows  how  to  arrange  one  of  the  coils  A, 
the  compass  E,  the  support  D,  and  the  battery  as  a 
galvanometer.  Place  the  coil  so  that  its  length  is  east 
and  west  and  place  the  compass  over  the  coil.  The 
needle  will  lie  crosswise  of  the  coil.  When  the  current 


Fig.  230.  Sucking  Coil.  Fig.  231.  Lines  of  Magnetic  Force. 

flows  the  needle  is  turned  from  its  north  and  south 
position.  The  laws  and  meaning  of  this  is  explained 
fully  in  the  text  books  of  electricity. 

Electroplating  has  become  one  of  the  most  important 
industries.  It  can  be  performed  with  the  apparatus  of 
Fig.  228.  The  arrangement  is  the  same  as  that  of  Fig. 
226,  except  that  the  tumbler  is  now  to  be  filled  with  a 
liquid  containing  the  metal  with  which  the  article  is 
to  be  plated.  To  plate  with  copper  a solution  of  copper 
sulphate  may  be  used,  though  carbonate  of  copper  is 
better;  for  nickel  a double  carbonate  of  nickel  and 
ammonia  is  used.  The  metal  will  be  deposited  on  the 


252 


llOMK  MECHANICS  FOI!  A.M A'l’KU l!8 


strip  attaclied  to  the  wire  from  tlie  zinc,  tliat  one  on 
wliich  tlie  h.ydrogen  appeared  when  water  was  d(*com- 
posed.  The  other  strip  must  he  of  the  metal  with  which 
tlie  plating  is  to  be  done. 


Fio.  232.  Mode  of  Inducing  an  Electric  Current  by  a Magnet. 

More  instruction  and  much  experience  will  be  re- 
quired for  real  work;  but  much  pleasure  can  be  de- 
rived by  watching  the  process  in  this  simple  manner. 
Three  or  four  cells  should  be  used  for  depositing  nickel. 

If  a copper  wire  is  passed  straight  through  the  fix- 
ture D,  and  the  parts  are  set  up  as  in  Fig.  229,  it  will 
constitute  a detector  galvanometer,  suitable  for  large 
currents,  as  the  arrangement  in  Fig.  27  is  adapted  for 


Fici.  233.  Mode  of  giving  an  Electric  Shock. 

fcclile  currimts.  The  wire  in  all  cases  must  be  placed 
noi-th  and  south,  or  lengthwise  of  the  needle  when  at 


rest. 


vei-y  many.  It  is  tli(‘  most  imiiortant  piece  of  electrical 


HOME  MECHANICS  FOR  AMATEURS  253 

apparatus,  aud  was  iuvented  by  Sturgeon  of  England 
and  also  by  Prof.  Joseph  Henry  in  America.  Probably 
neither  knew  the  work  of  the  other.  Henry’s  inven- 
tion led  directly  to  the  electric  telegraph.  Fig.  231)  is 
given  as  an  illustration  of  the  power  of  a helix  to  draw 
iron  or  steel  into  itself.  If  a strong  battery  is  used 
the  pen  is  sucked  into  the  coil  with  considerable  force. 
A large  number  of  small  wire  nails  may  also  be  held 
up  in  the  coil  without  visible  support.  It  is  Avizard- 


Fig.  234.  Microphone, 


like  to  see  a piece  of  heaA'y  metal  hanging  in  the  air 
upon  nothing.  Numerous  modifications  of  this  curious 
experiment  Avill  suggest  themselves  to  an  ingenious 
person. 

With  the  tAvo  coils  A,  put  upon  a U-shaped  iron 
rod  I inch  thick,  as  in  Fig.  231,  the  beautiful  mag- 
netic phantom  or  magnetic  field  of  force  can  be  made 
visible.  The  wires  from  the  spools  are  connected  to 
the  battery,  Avhich  is  not  shoAvn.  Join  the  tAVO  spools 
together  so  that  the  outside  of  the  Aviuding  of  one  is 


254 


llOMK  ME('IIAN1(!S  FOlt  AMATKUJJS 


coniH’cted  to  tlio  inside  of  the  windin'^  of  tlie  otlier.  A 
tliin  board  is  laid  over  the  poles  aTid  iron  filin<j;s  sifted 
over  the  board.  Then  tap  the  board  <f(‘ntly  with  the 
tip  of  a finger.  The  filings  jump  with  sudden  alac- 
rity into  lines,  definite  and  exact.  The  figure  shows 
these  lines.  It  means  magnetic  attraction.  Now 
change  the  connections.  Join  the  two  outside  wires  of 
the  spools  to  the  battery  and  the  inside  wires  to  each 
other.  The  figure  changes  to  one  exhibiting  repulsion. 
The  lines  shun  each  other. 

If  blue  print  paper  be  ])inned  on  the  board  and  the 
whole  exposed  in  the  sunlight,  fine  photographs  may 


Pig.  235.  Electromagnet  for  Lifting. 

be  made  of  these  beautiful  figures.  By  using  horse 
shoe  and  bar  magnets,  endwise  and  flatwise,  a great 
variety  of  magnetic  fields  may  be  mapped. 

Next  arrange  tbe  apparatus  as  in  Fig.  232.  The 
compass  m-t'dle  is  strongly  deflected  from  its  north  and 
south  jmsition.  Now  remove  the  battery  and  close  the 
circuit.  Blunge  a bar  magnet  into  the  right  hand  coil. 
1’he  ni'edle  swings,  though  not  so  strongly  as  before. 
.An  electric  curnmt  is  gmierated  so  long  as  the  magnet 
is  in  motion,  (‘ith(‘r  in  or  out  of  the  coil. 

If  the  cores  of  tlnj  coils  in  hfig.  232  are  filled  Avith 
iron  wires  a cnrrmit  may  b(‘  generated  by  simply  tak- 


HOME  MECHANICS  FOR  AMATEURS 


255 


ing  the  right  hand  coil  in  the  hands,  holding  it  north 
and  south  and  turning  it  over  quickly.  These  effects 
were  discovered  by  Ampere,  for  whom  the  unit  of  cur- 
rent is  named.  The  student  should  look  up  the  subject 
in  text  books  of  electricity. 

The  giving  of  electric  shocks  to  one’s  friends  is  al- 
ways a pleasant  pastime.  One  mode  of  doing  this  is 
illustrated  in  Fig.  233.  Of  course  no  severe  shock  can 
be  given  in  this  way.  The  metal  handles  of  Fig.  238 
should  be  connected  to  the  open  ends  of  the  wires  to 


Fig.  236.  Electric  Telegraph. 


the  left.  Scrape  the  ring  along  the  file  and  a slight 
shock  will  be  felt  by  one  whc  grasps  the  handles  with 
moist  hands.  The  shock  is  produced  by  an  induced 
current.  The  arrangement  is  a very  simple  form  of 
induction  coil.  As  the  making  of  a strong  coil  is  a 
difficult  matter,  a special  and  full  description  of  the 
coil  to  be  made  should  be  obtained  before  undertaking 
such  a piece  of  work. 

Fig.  234  is  a microphone.  Two  bits  of  iron  wire,  or 
bright  wire  nails,  p,  are  connected  to  the  wires  and  laid 


25(! 


IlOMI-:  MKCIIANK'S  KOI!  AMATKKliS 


oil  (lie  to])  of  a box  iiiadc*  of  fhiii  wood  as  shown.  Pine 
is  to  be  jireferri'd.  A slieet  of  iron  is  laid  njion  tb(‘  toj) 
of  the  eleetroinasnet.  On  tajijiinj^-  (lie  box  gently  a 
inneb  louder  sound  will  b(‘  beard  from  the  sbeid  of 


Fig.  237.  Dynamo  or  Motor. 


of  the  invention  of  the  transmitter  of  the  telephone. 
If  a telephone  receiver  is  used  in  place  of  the  electro- 
magnet and  sheet  of  iron,  the  feeblest  sounds  produced 
on  tlie  top  of  the  box  are  greatly  intensifled.  The 
microphone  box  may  even  be  used  as  a telephone  trans- 
mitter if  tlie  wires  are  long  enough  to  permit  it  to  be 
T;lac(Hl  in  another  room,  and  all  the  parts  are  suffi- 
ciently delicate. 

Tlie  arrangement  of  an  electromagnet  for  lifting  pur- 
fioses  is  shown  in  Fig.  285.  By  means  of  a spring 
balaiic(*  oiK^  may  find  ilu^  ])ull  necc^ssary  to  remove  the 
annatnr(‘  wIkmi  11i(‘  niimbei'  of  (‘(^lls  of  the  battery  is 
vni'icMl  from  oik^  (‘(*11  ii])  to  ils  full  (‘apacity.  The  iron 
bur  iis(*(l  as  an  annatur(^  should  always  be  as  large  in 
cross  S(*cliou  as  I Ik*  iron  coih^  of  llu^  magmd. 


HOME  MECHANICS  FOR  AMATEURS 


257 


Fig.  236  will  guide  one  in  setting  up  a telegraph  line, 
with  a station  at  each  end.  The  key  is  simply  a strip 
of  spring  sheet  brass.  When  not  in  use  it  is  pressed 
down  and  caught  under  the  head  of  the  screw  beyond 
it  so  as  to  close  the  circuit.  The  construction  of  the 
sounder  is  so  simple  that  it  will  not  be  given  in  detail. 
The  most  difficult  part  to  adjust  is  the  vibrating  arm, 
m,  whose  blows  against  the  slot  in  the  post  to  the  right 
produce  the  sound  which  gives  the  name  to  the  instru- 
ment. The  vibrating  bar  should  not  strike  the  electro- 
magnet Avhen  it  is  pulled  down,  nor  have  a very  wide 
range  of  motion.  The  bar  must  either  he  wholly  of 
iron,  or  better,  have  a block  of  iron  riveted  to  it,  since 
brass  is  not  attracted  bv  a magnet.  The  tension  of  the 
fine  wire  spring  on  the  left  determines  the  force  neces- 
sary to  pull  the  bar  down. 


Fig.  238.  Shocks  by  Rotating  Coil. 


To  work  the  telegraph  swing  tlie  key  from  under  the 
head  of  the  screw  which  holds  it  down.  This  opens 
the  circuit.  The  bar  of  the  sounder  flies  up.  Now, 
press  the  key  down  till  it  touches  the  wires  below  it. 
The  current  from  the  battery  flows  and  the  armature 
is  jerked  down,  giving  a sharp  blow  on  the  post  Avhich 
detains  it.  As  the  kej^  is  moved  down  and  up  the  arma- 


258  liOMP]  MECJIANICS  FOE  AilATFUJJS 


tiire  moves  down  and  nj),  ])r(»dncinj;'  iln*  clicks  wliicli 
all  have  heard  in  a t(‘l(“i>ra])h  <»nic(‘. 

By  i’(*ttin,n'  a Morse  al])liahet  and  niastcrin_<j  tlie  art 
of  i)i‘odncin<^  dots  and  dashes  two  ])ersons  may  soon 
learn  to  send  messai^es  to  each  other. 

A model  of  a dynamo  may  he  hnilt  from  the  parts, 
A,  B and  C,  of  the  cahimd.  This  is  shown  in  Fiij.  2.37. 
The  electro-maju'net  formed  hy  A and  B is  fixed  upon  C, 
and  the  circuit  completed  hy  short  pieces  of  ma^^net 
wire.  The  open  ends  to  the  h‘ft  may  he  connected  to 
the  galvanometer,  I)  and  FI,  to  detect  the  current. 

The  rotating  coil,  H,  and  tlie  commntator  -T,  are 
somewhat  difiticnlt  of  constrnction.  The  coil  consists 
of  about  100  turns  of  Xo.  20  single  cotton-covered 
magnet  wire.  The  inner  end  of  the  wire  is  soldered  to 
one  of  the  half  rings  of  the  commntator,  the  outer  end 
to  the  other  half  ring. 

On  whirling  the  coil  rapidly  a feeble  current  will  be 
produced.  The  current  will  he  reversed,  if  the  coil  is 
whirled  in  the  opposite  direction. 

This  tiny  dynamo  may  be  transformed  into  a series 
wound  motor  hy  connecting  the  battery  in  place  of  the 
galvanometer. 

By  changing  the  connections  as  shown  in  Fig.  238, 
the  electric  current  may  be  felt  in  the  handles  when  the 
armature  is  whirled  rapidly. 

Though  the  experiments  described  by  no  means  ex- 
haust the  subject,  nor  the  resources  of  the  electrical 
cabinet,  still  they  jdace  Ixdore  the  studious  amateur 
enough  to  em|)loy  many  an  hour  most  profitably,  and 
to  incite  him  to  further  study  and  to  higher  work. 


HOME  MECHANICS  FOR  AMATEURS 


259 


SIMPLE  ELECTRIC  MOTOR 

Almost  every  young  amateur  mechanic  is  desirous 
of  making  sometliing  liaving  the  ability  to  move  and 
show  action.  An  electric  motor  does  this;  and  while 
the  mechanic  is  making  a good  piece  of  machinery, 
he  is  also  learning  the  principles  of  electricity. 

The  motor  we  shall  describe  is  intended  to  turn  a fan 
or  light  machinerv  bv  means  of  a current  derived  from 
a battery.  It  will  drive  a light  sewing  machine  or 
other  machinery  requiring  a similar  amount  of  power, 
and  it  is  so  simple  as  to  admit  of  being  constructed 
with  the  tools  ordinarily  possessed  by  an  amateur. 

To  begin  a motor  at  the  right  point  is  very  import- 
ant. The  first  thing  to  be  done  is  to  construct  the 
armature — the  part  which  revolves.  On  account  of  its 
simplicity,  we  have  selected  the  Gramme  armature. 

The  core  of  this  armature  consists  of  a ring  formed 
of  No.  24  sheet  iron.  A strip  f inch  wide  and  8 feet 
long  (the  length  of  a sheet)  is  carefully  cut  from  the 
sheet  and  wound  upon  a cwlindrical  piece  of  wood  in 
the  lathe  or  by  hand.  The  wood  cylinder  is  If  inches 
in  diameter  and  1 inch  thick,  and  in  the  edge  is  cnt  a 
shallow  notch  of  a depth  equal  to  the  thickness  of  the 
sheet  iron,  as  shown  in  Fig.  240.  In  the  iron,  ^ inch 
from  the  end  is  drilled  a hole,  countersunk  to  receive 
a wood  screw,  which  passes  through  the  sheet  iron 
into  the  wood,  and  fastens  the  end  in  the  notch  in  the 
wood.  The  sheet  iron  thus  attached  to  the  wood  may 
be  wound  closely  around  the  wooden  mandrel  withoiit 
a kink  being  formed  by  the  inner  end  of  the  strip, 
which  is  in  the  notch. 

Before  beginning  the  winding,  a piece  of  strong  an- 


260  HOME  MECHANICS  EOK  AMATEUES 

nc“al(‘(l  wire,  slovc'-pipe  wire  for  example,  is  jEaced  in 
a liandy  position,  and  when  nine  layei'S  of  Hie  iron 
have  been  wound  tlie  striji  is  ent  off  and  Hie  liindini^ 
wire  is  wrapped  around  Hie  coil  and  twisted  toiiether 
at  the  ends,  to  keep  the  sheet  iron  from  unwinding. 


Fig.  239.  Electric  Motor. 

The  wood  and  tin*  coiled  sheet  iron  are  together 
removed  from  (In*  hiHu*  (or  vis(‘  if  it  is  being  done  by 
hand),  and  placed  in  a lir(‘,  which  will  h(“at  the  iron 
to  a cherry  red  and  burn  out  the  wood.  The  ring  is 


HOME  MECHANICS  FOR  AMATEURS 


261 


then  covered  with  ashes  and  allowed  to  cool  slowly. 
This  anneals  the  iron,  and  improves  its  magnetic  per- 
meability. 

After  removal  from  the  ashes,  and  while  the  binding 
Avire  is  still  in  place,  the  ends  are  secured  by  passing 
riA'ets  through  them ; the  inner  end,  which  AA’as  bent,  is 
cut  off,  and  the  ends  are  beveled  Avith  a tile,  and  all 
the  sharp  corners  are  reduced  by  the  same  means. 

The  core  of  the  armature  is  then  covered  with  adhe- 
siAm  tape  (either  electi’ical  or  bicwcle  tire  tape),  AA'hen  it 
is  ready  to  receiA'e  the  magnet  Avire  Avith  Avhich  it  is  to 
be  AA’Ound.  The  ring  is  diAuded  into  tiA^e  equal  sec- 
tions, and  marked  Avith  a pencil  to  shoAV  Iioav  much 
space  each  coil  of  the  armature  is  to  occupy.  There 
are  five  coils  on  the  armature,  Avith  five  laj'Ci’s  in  each 
coil.  No.  21  single  or  double  cotton  or  silk  coA^ered 
wire  is  used.  It  requires  about  28  feet  of  Avire  for  each 
coil.  The  Avinding  is  a.  sIoav  and  rather  laborious 
process.  The  length  of  Avire  for  a coil  is  Avound  on  a 
sort  of  shuttle-stick  J inch  Avide,  12  inches  long,  Avith 
a notch  in  each  end.  The  end  of  the  Avire  is  Avrapped 
twice  or  three  times  around  the  ring  over  a piece  of 
stout  thread,  Avhich  is  tied  around  the  Avires  to  fasten 
them  together,  to  begin  a coil.  Of  coiirse,  the  begin- 
ning is  at  one  of  the  marks  on  the  ring. 

Noav  the  shuttle  is  passed  through  the  ring  and 
brought  back  oA’er  the  outside  until  one  layer  covers 
one  space;  then  commencing  the  Avindiug  oA^er  the 
first  layer  the  second  is  laid  on,  then  the  third,  fourth, 
and  fifth;  all  the  layers  are  AA’ound  in  the  same  way. 
The  last  three  or  four  turns  are  mad(?  over  a stout 
thread,  Avhich  is  tied  Avhen  the  last  convolution  is 
made. 


2C2 


HOME  MEOTIANICS  EOE  AMATEUES 


Tlio  otlioi'  coils  of  the  iiniialnit*  ar(^  made  in  the 
same  way,  and  wlum  tin"  winding  is  all  on,  the  end  of 
one  coil  is  f\vist(“d  with  Ihe  heiiinninn’  of  tin*  adjac(*nt 
coil.  A piece  of  well  season<‘d  hard  wood,  hai'd  mapl(“, 
for  exam])le,  is  horc'd  to  rec(‘iv(‘  a ]dece  of  inch  drill 
rod — Stnhs  or  sonndhinj;'  ecpially  n'ood — which  consti- 
tutes the  shaft.  This  rod  is  4 inch(>s  lon<i'.  A iV  inch 
Inde  is  drilled  transversedy  thronjih  it  at  or  near  the 
center  to  receive*  a short  pin  which  enters  a slot  in  the 
end  of  the  wooden  hnb. 

This  i)iece  of  wood  is  turned  to  tit  the  interior  of  the 
armature,  and  is  ent  off  ahont  tin*,  same  length  as 
the  armature.  The  coils  of  the  armature  and  the 
Avooden  hnh  are  now  varnished  with  thin  shellac  var- 
nish, and  allowed  to  dry  thoroughly.  The  armature 
ring  is  then  slipped  into  its  place  on  the  wooden  huh, 
and  the  hnh  and  the  ring  are  coated  with  two  coats  of 
shellac  varnish,  one  coat  being  allowed  to  dry  before 
applying  the  other. 

The  next  thing  to  claim  attention  is  the  commutator. 
This  is  a core  of  wood  fitted  to  the  armature  shaft  and 
turned  to  fit  a piece  of  brass  or  copper  tube  f or  f 
inch  in  diameter  and  f inch  long.  This  tube  is  divided 
into  five*  divisions,  and  parallel  lines,  preferably  slightly 
spiral,  are  drawn  from  the  divisional  points  marking 
the  ]tlac<*s  wh(*r(‘  the  tube  is  to  be  saAved  to  form  the 
commutator  bai's.  But  Ix'fore  saAving,  each  end  of 
each  s]>ac(*  Avhich  is  to  form  a bar  is  drilled,  and  the 
hob*  is  conntei-snnk  to  rec(*ive  a small  Avood  screAA*, 
which  ]»asses  into  tin;  wood  and  holds  the  bar  in 
plac(*  when  lln*  brass  tnlx*  is  saAved  on  the  lines  to 
separa((‘  the  bars.  After  sawing,  the  commutator  is 
turn(*d  smooth  and  round,  or  filed  in  the  lathe  Avith  a 


HOME  MECHANICS  FOR  AMATEURS  363 


smooth  file.  The  screws  used  in  fastening  the  commu- 
tator bars  must  not  touch  each  other  or  the  shaft. 

The  twisted  terminals  of  the  coils  are  now  stripped 
of  the  winding  at  the  ends  and  soldered  to  the  commu- 
tator bars,  having  been  cut  off  the  proper  length  to 
reach  to  the  commutator. 

Before  soldering,  however,  the  ends  of  the  terminals 
and  a small  portion  of  each  commutator  bar  are  tinned 
to  facilitate  the  work  of  soldering.  To  tin  the  copper 


Fig.  240.  The  Armature  Core. 

wire,  a little  pulverized  rosin  is  rubbed  on  the  ends  of 
the  wires,  and  the  solder  is  applied  with  a soldering 
iron. 

Tlie  commutator  bars  are  tinned  for  inch  at  the 
ends  nearest  the  armature  ring  in  the  same  manner. 

The  terminals  of  the  armature  coils  are  bent  so  as 
to  touch  the  commutator  bars  at  the  tinned  surfaces; 
the  beginning  of  one  coil  and  the  end  of  the  adjacent 
coil  being  thus  brought  into  contact  with  a commutator 
bar.  They  are  then  soldered  by  applying  a drop  of 
solder  by  means  of  the  soldering  iron.  The  wires  are 


264 


HOME  MI^CMIAN K^S  FOl?  AMATKUKS 


tlnis  made  to  answer  tln^  (loiil)l(^  ])nr])()S(‘  of  (*onv(‘vin^ 
tile  enrreiit  to  the  eoiniiiiitalor  bars  and  of  (‘ansinu^  tin* 
eoinnuitalor  to  revolve  with  the  annatnri*.  Arid  must 
not  be  used  in  soldering’  (4(‘('tri(‘al  eoniuHd ions. 

To  rnn  smoothly,  the  armatnr(‘  must  be  in  balan(‘(\ 
To  ascertain  Avheth(‘r  it  is  in  balam-e,  ])lace  tin*  arma- 
ture shaft  on  the  (m1il»(‘s  of  two  l(‘V(d  straii»ht-(*diL»;(‘s  sup- 
ported about  4 iiK'hes  ajiart.  If  the  armature  will 
stand  in  any  position,  it  is  balanccMl.  If  it  rolls  so  that 
one  side  after  a few  os(‘illations  of  tln^  aianatnre  i»()(^s  to 
the  bottom,  the  to])  must  be  made  heavier  to  ('onntin'- 
balanee  the  bottom.  Jb'obably  the  Ix^st  Avay  to  add 
weight  to  one  side  of  the  armature  is  to  apply  it  in  the 
form  of  solder  to  a band  of  wire  abont  f inch  wide 
wound  aronnd  the  armature.  Ilefore  this  winding  is 
applied,  a strip  of  mica  f inch  wide  must  be  wrapped 
around  the  armature  and  secured  in  place  by  shellac 
varnish  applied  to  both  the  armature  and  to  the  mica 
and  allowed  to  become  nearly  dry.  It  is  not  necessary 
to  nse  a continnons  piece  of  mica ; it  may  be  in  several 
pieces.  When  the  armature  comes  to  rest  after  oscilla- 
tion, solder  should  be  applied  to  the  upper  side  of  the 
wire  band  until  the  armature  will  stand  in  any  posi- 
tion. If  too  much  solder  is  applied,  the  surplus  may  be 
removed  by  a coarse  file.  It  is  important  to  have  the 
armature  as  nearly  in  balance  as  jiossible.  It  will  then 
liave  \ory  little  vibration,  or  none  at  all,  while  running 
at  any  rc^asonable  sjxhhI. 

(Airc^  should  Ix^  ns(‘d  in  all  the  operations  connected 
with  this  motor  to  insure  entire  siu'cess. 

Th(^  n(‘\t  thing  to  b(‘  done  is  to  construct  the  field 
magiK't,  which  in  this  motor  is  in  the  form  of  a ring, 
as  shown  in  hhg.  241.  The  cor(‘  of  the  field  magnet  is 


HOME  MECHx\NICS  FOR  AMATEURS 


265 


formed  by  winding  four  strips  of  No.  24  sheet  iron  f 
inch  wide  and  8 feet  long  upon  a wooden  core,  as  in  the 
case  of  the  armature  core.  The  form  on  which  the 
field  magnet  is  wound  being  inch  larger  in  diameter 
than  the  armature,  and  as  this  is  variable,  it  must  he 
ascertained  after  the  armature  is  wound  and  balanced, 
on  account  of  the  variation  in  the  winding  depending 
on  the  covering  of  the  ware  and  the  care  with  which  it 


Fig.  241.  Field  Magnet  Core. 

is  wound.  In  the  motor  illustrated,  the  field  magnet 
ring  is  2f  inches  internal  diameter  and  44  inches  ex- 
ternal diameter.  Before  winding  the  field  magnet  core, 
the  ends  of  the  8-foot  strips  are  scarfed  or  beveled  off 
and  tinned,  and  then  soldered  together  and  coiled  for 
convenience. 

The  strips  should  be  wound  upon  the  form  as  tightly 
as  possible,  and  when  the  last  layer  is  on,  a stout  wire 
is  wrapped  around  the  outside  and  twisted  together  to 


2r,r,  TTOMP]  MECHANICS  VOM  AAIA^rKlIK’S 


keo])  the  sluH^t  iron  stri])  fi'oin  nnwiii(liii^,  as  in  11i(^ 
ease  of  tln^  arinatiire  (‘or(‘. 

As  it  is  not  nec-essary  to  ann(‘al  th(‘  Ii(‘l(l  ina<»:n(‘t,  the 
wooden  form  is  r(miOA(‘d  by  boring  a liole  Ilironi»ii  it 
and  tlien  splitting  the  wood  so  that  it  (*an  Ix^  r(miov(xl 
piecemeal.  The  coil  of  she(d  iron  foimiing  iln^  field 
magnet  core  is  eomposcMl  of  thirty-thix^e  lay(‘rs. 

The  ring  is  divided  into  four  qnartm's  by  radial  lim^s, 
and  midway  between  two  of  these  lines,  on  o])])osit(^ 
sides  of  the  ring,  are  drilled  holes  for  rivets  im-h  in 
diameter,  the  holes  being  (*onntersnnk  slightly  on  (‘ach 
side.  These  rivets  with  slight  heads  are  inserted  in 
the  holes,  with  the  heads  inside  the  ring.  They  are 
then  neatly  riveted  at  the  outside,  leaving  the  inner 
side  as  smooth  as  possible.  To  accomplish  this,  it  is 
necessary  to  move  the  binding  wire  away  from  the 
center  of  the  field  magnet  ring. 

When  the  two  rivets  are  in  the  binding  wire 

mav  be  removed;  then  in  the  same  sections  near  the 
ends  are  placed  rivets,  one  at  each  end  of  each  section. 
Tlie  sections  riveted  in  this  manner  form  inwardly 
projecting  pole  pieces.  While  drilling*  the  holes  for 
the  rivets,  it  is  necessary  to  clamp  the  strips  firmly  to- 
gether to  prevent  the  drill  chips  from  working  in  be- 
tween the  layers  of  the  magnet.  Eleven  layers  of  the 
magnet  ring  are  sawed  ont  between  the  pole  pieces  to 
make  a space  for  the  w'inding  of  the  field  magnet;  the 
ends  of  the  ynde  pieces  are  beveled  as  shown  to  facili- 
tate winding.  Th(“S(*  spaces  are  covered  with  adhesive 
tape  and  ar(‘  wound  with  four  layers  (about  45  feet)  of 
\o.  18  magnet  wire,  either  single  or  double,  cotton  or 
silk  cover(‘d. 

One  of  the  y)ole  pieces  will  be  at  the  bottom  of  the 


HOME  MECHANICS  FOR  AMATEURS 


267 


field  magnet  and  the  other  at  the  top  when  the  motor 
is  complete;  therefore  the  winding  on  each  side  of 
the  field  magnet  begins  at  opposite  sides  of  the  same 
pole  piece,  and  is  wound  in  the  same  direction  to  bring 
the  wire  terminals  near  the  base  of  the  machine,  and 


to  cause  the  current  in  the  two  windings  to  unite  in 
producing  a north  pole  at  the  top  of  the  magnet  and  a 
south  pole  at  the  bottom,  or  vice  versa.  If  a mistake 
is  made  in  the  winding,  this  can  be  corrected  in  making 
the  connections.  It  is  not  necessary  to  unwind  and 
rewind. 


208 


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The  constniction  of  tliis  inajiiiol  is  ojxoi  lo  criticism 
oil  account  of  the  disposition  of  tin*  lainimo,  but  this 
constniction  is  partly  or  wholly  compensated  for  by  tin* 
large  rivets,  which  bind  the  jiole  pieces  and  the  body 
of  tlie  magnet  together. 

The  holes  are  drilled  in  the  lower  side  of  the  magnet 
and  tapped  to  receive  machine  screws,  which  jmss  n])- 
ward  throngh  the  base  of  the  machine  to  hold  the 
magnet,  which  latter  sits  njion  a small  wooden  saddb^ 
about  ^ inch  thick  in  the  middle.  The  field  magnet 
winding,  as  well  as  the  iion  core,  is  covered  with  sev- 
eral coats  of  shellac  varnish,  for  insulation  and  protec- 
tion. 

The  journal  boxes  for  the  shaft  are  simply  f brass 
balls  axially  bored  to  receive  the  shaft,  and  having  an 
oil  hole  in  the  top.  These  boxes  are  each  held  in  place 
by  two  brass  plates  bored  to  receive  the  sides  of  the 
lialls  as  shown,  and  attached  to  the  sides  of  the  square 
wooden  standards  by  screws.  The  shaft  is  allowed  to 
project  at  one  or  both  ends  sufficiently  to  receive  a 
jiulley  or  fan.  The  armature  is  w^rapped  around  the 
sides  with  enough  firm  paper  to  cause  it  to  fit  tightly 
into  the  field  magnet,  and  after  the  shaft  is  made  level, 
the  journal  boxes  are  placed  on  the  shaft,  and  the 
standards  which  support  them  are  sawed  off  the  prop- 
er length  and  secured  to  the  base  by  screws,  one  for 
(‘ach  standard,  passing  upwardly  througb  the  base  and 
iulo  the  low'(‘r  mids  of  the  standard.  To  the  base  ad- 
joining th(‘  standard  at  tin*  commutator  end  is  attached 
a wooden  block,  to  tin*  ends  of  which  are  secured  light 
copfier  sjirings,  which  b(‘ar  on  opposite  sides  of  the 
commutator  and  act  as  brushes  for  conveying  the  cur- 
rent lo  the  armature. 


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269 


The  screws  which  hold  tlie  lower  ends  of  these 
brushes  also  clamp  the  wires  which  extend  downward 
through  the  base,  one  being  connected  with  one  of  the 
binding  posts  which  receive  the  battery  wires,  the 
other  brush  being  connected  with  the  outside  terminal 
of  one  of  the  field  magnet  coils.  The  outside  terminal 
of  the  other  field  magnet  coil  is  connected  with  the  re- 
maining binding  post.  The  inside  terminals  of  the 
field  magnet  coils  are  connected  together.  The  con- 
nections are  clearly  shown  in  the  diagram  (Fig.  242). 
The  upper  screws  in  the  commutator  brushes  are  used 
for  varjdng  the  pressure  of  the  brushes  on  the  com- 
mutator as  may  be  required;  the  brushes  being  bent 
outwardly  to  admit  of  this  adjustment. 

If  the  motor  is  to  be  used  for  driving  a fan,  the  base 
will  need  to  be  set  upon  legs  of  some  kind.  In  the 
motor  illustrated,  the  base  is  supported  upon  four  in- 
verted clothes  hooks  Avhich  support  it  2 inches  from  the 
table. 

The  oil  cups  are  made  of  wood  (soft  maple  or  birch), 
with  stems  extending  down  into  the  fV  holes  in  the 
spherical  boxes;  and  in  the  portion  of  the  wood  above 
the  journal  box  is  formed  a cavity  which  will  contain  a 
few  drops  of  oil.  The  outside  of  the  oil  cup  is  varnished 
with  shellac  except  at  the  end  of  the  stem,  before  any 
oil  is  put  in.  This  confines  the  oil  to  the  cavity  and 
the  interior  of  the  stem  and  causes  it  to  slowly  feed  to 
the  journal  on  which  the  stem  rests.  The  fan  can  be 
purchased  for  a small  sum.  It  may  be  necessary  to 
bush  it  to  fit  the  shaft.  Either  an  8-inch  or  a 10-inch 
fan  may  be  used. 

Of  course,  a small  pulley  will  be  substituted  for  the 
fan  when  the  motor  is  used  to  drive  a machine. 


370  HOME  MECHAISrrCS  FOI?  AMATEURS 


If  tlie  motor  wlioii  finisliod  (lo(*s  not  run  in  tlie  do- 
sired  direction,  this  may  he  chaniLied  l)y  transposiiii^  tluj 
wire  connections  at  the  hrnshes,  so  as  to  cliange  the 
direction  of  the  current  in  tlie  armature. 


SMALL  ELECTKIC  MOTOKS  FOK 


A:MATEUTtS 


Every  piece  of  electric  work  done  hy  a student  or 
amateur  is  of  vahn*,  not  only  as  an  addition  to  his 
collection  of  ap])aratus,  but  as  a means  of  accpiiring  a 
positive  knoAvledge  of  electricity  and  of  electrical  appa- 
ratus. The  following  engravings  show  a simple  and 
easilv  constructed  motor,  which  verv  fuliv  illustrates 
the  construction  and  operation  of  the  (Iramme  motor, 
and  is  well  adapted  to  various  uses  requiring  only  a 
small  amoAint  of  power. 

This  motor  Avas  built  by  ]\Ir.  W.  S.  Bishop,  of  Ncaa' 
IlaA'en,  Conn.,  after  the  general  plans  of  the  simple 
electric  motor  alreadv  illustrated  and  described  in  a re- 
cent  Scientific  American,  but  the  construction  here 
shoAvn  is  more  simple  and  more  easily  carried  out. 
The  perspective  vieAV  here  given  is  tAA'o-thirds  the 
actual  size.  The  front  and  side  eleA'ations  and  the 
smaller  detail  vieAV  are  full  size. 

Th(“  field  inagnet.  A,  is  formed  of  a yoke  of  NorAA’ay 
iron  inch  thick,  J inch  Avide  and  2^  inches  long. 
In  tin*  yok(*,  lu'ar  its  ends  and  lA  inches  apart,  are 
<lrilled  hoh's  for  r(“C(uving  the  (piarter  inch  Norway 
in)n  cores  of  tlu'  magnet,  AAdiich  are  driA'en  into  the 
A’oke. 

Tli(*  polar  a,  of  tlu^  field  magnet  are 

(an‘\(*(l  to  form  a eircailar  opeiiiiii;'  2tV  iiu'lies  in  diam- 
(*t(*r.  Tli(‘  \vindiiii»  of  the  field  magnet  may  be  applied 


HOME  MECHANICS  FOR  AMATEURS 


271 


to  the  magnet  cores,  as  shown  in  the  engraving,  or  the 
wire  may  be  Avoiind  upon  spools  fitted  to  the  cores. 
The  spools  are  1 inch  in  diameter  and  1-J  inches  long  be- 
tween the  heads.  Upon  each  spool  is  wound  1 ounce  of 
No.  24  double  wound,  cotton  covered  magnet  wire.  The 
yoke  of  the  field  magnet  is  fastened  to  the  wooden 
base  piece  of  the  motor  by  screws  passing  upwardly 
through  the  base  into  threaded  holes  in  the  yoke. 

The  armature,  B,  consists  of  a small  Gramme  ring 
mounted  upon  a Avooden  disk  secured  to  the  armature 
shaft.  The  armature  core,  c,  is  a ring  formed  of  a piece 
of  annealed  iron  Avire,  No.  13  B.  & S.  gauge,  hUAung  its 
ends  beA’eled  and  drilled  transA^ersely  to  receiA^e  a pin, 
as  shoAvn  in  Fig.  246.  A core  of  this  kind,  although 
theoretically  not  as  efficient  as  a laminated  core, 
ansAvers  every  purpose  in  this  A'ery  small  motor,  and 
greatly  facilitates  the  construction  of  the  armature. 
The  core  has  an  outside  diameter  of  If  inches.  The 
outside  diameter  of  the  armature  is  2 inches,  and  the 
inside  diameter  If  inches.  Upon  the  armature  core 
are  placed  12  coils,  l>,  of  silk  coA^ered,  single  AAmund  mag- 
net Avire,  No.  25  B.  & S.  gauge,  separated  by  rings  d of 
soft  iron  Avire  No.  13,  the  rings  forming  polar  exten- 
sions AAdiich  add  to  the  efficiency  of  the  motor.  The 
armature  coils  are  formed  in  a lathe  on  a mandrel, 
separately,  as  shoAvn  in  Fig.  247.  This  mandrel  con- 
sists of  a piece  of  No.  11  Avire  liaAdng  Iaa’o  collars  f of  an 
inch  apart,  one  of  the  collars  being  fixed  and  the  other 
being  removable.  Each  coil  contains  4 feet  4 inches  of 
wire  v.’ound  in  fiA  e layers. 

To  facilitate  the  removal  of  the  coil  from  the  man- 
drel, the  first  layer  is  AAmund  loosely.  After  winding, 
and  before  removing  the  coil  from  the  mandrel,  the  wire 


372  HOMI-]  MECHANICS  FOR  AMATEURS 


is  ceiuentcd  with  paraftiiu'^  or  wax  iiioltod  on  ilio  coil 
with  a warm  iron.  After  twelve  coils  have  heen  com- 
pleted, they  are  strung  upon  the  armature*  eon*,  c,  in 
alternation  with  the  iron  wire  rings,  d,  and  when  the 


Fig.  243.  Perspective  View  of  a Small  Gramme  Ring  Motor. 


is  fill(*(l,  its  (^iids  arp  bioui^ht  tojj^etlier  and  secured 
hy  iiKGUis  of  tli(^  pin,  as  sliown. 

Tli(*  \vood(‘ii  lnd)  of  t li(‘  arinaiiirc^  is  now  fitted  to  the 
]‘in^',  hat  Ixd'oi'e  lli(‘  rin<>'  is  secui'(‘d  on  tlie  linb,  twelve 


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273 


equidistant  holes  are  drilled  transversely  through  the 
huh,  near  its  center,  and  in  each  hole  is  inserted  a piece 
of  No.  12  copper  wire  one-half  an  inch  long.  The  ends 
of  the  pieces  of  copper  wire  are  allowed  to  project  one- 


Fig.  243  A.  Perspective  View  of  Small  Gramme  Ring  Motor. 

sixteenth  of  an  inch  beyond  the  sides  of  the  hub.  The 
ring  is  placed  on  the  hub,  and  the  ends  of  the  wire  pro- 
jecting from  adjacent  coils,  h,  are  twisted  together  and 
attached  by  means  of  solder  to  the  copper  wire  pins 


374  HOME  MECHANICS  FOR  AMATEURS 


(‘xtendinfj  tliroufj,!)  tlu*  hub  uiid  fonniiiii  coimiin- 
tator  bars,  tlie  cuverins^  bciiiij  rciiiuvcd  from  tli(*  cx- 
tromitios  of  tlio  wire.  It  will  finis  Ix'  sccui  that  to  <“acb 
commutator  bar  is  couiiccti'd  flic  Ix'^iunina;  of  one  coil 
and  the  end  of  the  adjacent  coil,  so  that  liy  means  of 


Pig.  244.  Sectional  Side  Elevation  of  a Small  Motor. 


these  connections  the  winding  of  the  armature  becomes 
continuous. 

The  ])osls  in  wliicb  tb(‘  armature  shaft  is  journaled 
are  pm  forated  ni'ar  tlnur  ujiiier  mids  with  a bole  of  a 
size  adajiled  to  ri'ciuve  tb(‘  armature  shaft,  and  these 
holes  are  countm-horixl  from  the  inner  surfaces  of  the 
posls,  and  a win*  of  ilie  same  diameter  as  the  shaft 


HOME  MECHANICS  FOE  AMATEHES  275 


is  placed  in  the  position  of  the  armature  shaft,  and 
Babbitt  metal  or  type  metal  is  poured  into  the  open- 
ings around  the  shaft,  forming  the  journal  boxes.  A 
hole  is  bored  in  the  top  of  each  post  before  casting  the 
metal,  to  form  an  anchorage  for  the  journal  box,  and 
after  the  casting,  the  anchorage  is  drilled  through  to 


Fig.  245.  Front  Elevation  of  Small  Motor. 


the  opening  of  the  journal  box  to  form  an  oil  hole  for 
the  armature  shaft. 

The  journal  box  on  the  side  of  the  commutator  is 
made  to  project  beyond  the  inner  face  of  the  post  to 
receive  the  disk,  f,  which  carries  the  commutator 
springs,  g.  This  projection  is  made  by  clamping  to  the 
post  a piece  of  wood  having  in  it  a hole  corresponding 


27G 


IIOMK  MKCIIAXICS  FOIJ  AAIATKUKS 


Avitli  tliat  ill  till*  ])ost.  After  tlx*  jonrnal  hox  is  cast, 
file  extra  jiiocc  of  wood  is  rciiiovod,  l(‘avinfj;  a sloovi* 
iijioii  wliicli  to  ])laee  tlie  disk,  f.  Tliis  disk  is  an  iiicli 
and  a lialf  in  diameter  and  Vo  of  an  iiieli  tliiek. 


Fig.  246.  Armature  of  Small  Motor  in  Process  of  Construction. 

To  tlie  inner  faee  of  tlie  disk,  /,  are  elamped  tlie  coin- 
nuitator  sprinj>s,  (/.  by  means  of  small  blocks,  as  shown 
in  the  perspective  view,  these  blocks  being  held  in  place 
by  screws  passing  through  the  disk  into  threaded  holes 


b 


Fig.  247.  Apparatus  for  Winding  Armature  Coils. 

in  ll)(*  blocks.  Tli(‘  (‘oiiiimitalor  s])riiii»s  ai'(^  curved 
on  I ward  ly  and  lh(*ii‘  (aids  ar(‘  tnriHal  baidcward  to- 
ward IIk^  disk,  /,  and  tlieir  (a\treniiti(‘S  i'(‘st  ii])oii  the 
(‘oiiiimilalor  bars,  as  show  n in  hd<;s.  243  and  244. 


HOME  MECHANICS  FOR  AilATEURS 


277 


The  disk,  f,  and  the  clanipiiig  blocks  are  made  of 
vulcanized  fiber,  which  is  strong  and  at  the  same  time 
a good  insulator.  The  commutator  springs,  g,  are 
made  of  hard  rolled  copper,  and  their  inner  ends  are 
adjusted  so  as  to  touch  diametrically  opposite  commu- 
tator bars.  The  best  adjustment  for  the  commutator 
springs  is  found  by  moving  the  disk,  f,  in  one  direction 
or  the  other.  It  will  he  found  that  the  maximum  ef- 
fect is  secured  when  the  contact  surfaces  of  the  com- 
mutator springs  are  nearly  in  a vertical  line. 

The  disk,  /,  is  clamped  in  any  desired  position  by  an 
ordinary  wood  screw,  li,  which  passes  looselj^  thrf)ugh 
the  post  and  is  screwed  into  a wooden  thumb  nut  bear- 
ing against  the  outer  surface  of  the  post.  The  ter- 
minals of  the  field  magnet.  A,  are  connected  directly 
with  the  binding  post  and  also  with  the  outer  ends  of 
the  commutator  springs,  g,  as  shown  in  Figs.  243  and 
245. 

With  one  cell  of  dry  battery  the  motor  makes  about 
1,800  revolutions  per  minute,  luit  it  does  not  develop 
its  maximum  power  until  one  or  two  cells  are  added  in 
parallel.  Any  of  the  dry  batteries  will  run  it  for  short 
periods,  but  if  it  is  required  to  run  it  continuously  for 
any  length  of  time,  one  or  two  cells  of  Bunsen  or  a 
Fuller  battery  shoiild  be  used. 

The  motor  being  shunt  wound,  is  practically  self- 
regulating.  Its  speed  with  any  amount  of  battery 
power  does  not  much  exceed  2,000  revolutions  per 
minute. 


278 


HOME  AIECIIANICS  EOE  AJIATEUES 


JlOW  TO  .MAKE  A SEWFXO  :\FA(''IIIXE  MOTOi; 

WITIIOET  ('ASTIXdS* 

The  acc(»)ni)iniyiiii>’  drawiiijns,  lojueilier  witli  llie  fol- 
lowiiij;:  instiaietioiis,  will  eiiabh*  any  iiiechaiiic  of  av<T' 
af>e  ability  to  build  a bi<ildy  (‘tticieiit  motor  that  will 
o])eratc  the  heaviest  of  family  sewiiij;'  machines  with  a 


Fid.  248.  Sewing  Machine  Motor  Made  by  an  Amateur. 

(•()nsinnj)l  ion  of  (‘l(‘(‘ti'i(‘al  eiior<>‘v  only  a trifle  ju^reater 
llnm  llial  r(*(niir(‘(l  lo  inaintain  an  iiu'andesc'oiit  lamp. 
All  Ilic!  mal(*rials  (‘nl(‘riniL>‘  into  ili(‘  (*onstrii('tioii  of  tlie 
inoloi'  may  Ix^  pi'ocniXMl  in  almost  any  town  or  small 


* Fy  Cecil  P.  Poole. 


HOME  MECHANICS  FOR  AMATEURS  279 


city,  and  the  total  cost  of  the  machine,  excepting,  of 
course,  the  labor,  should  not  exceed  five  dollars. 

The  first  operation  is  that  of  making  the  magnet, 
which  consists  of  a bar  of  ordinary  wrought  iron, 
inches  square  and  19  inches  long,  bent  (while  red  hot) 
into  a U,  as  shown  by  Fig.  248.  After  bending  the  iron 
into  shape,  cut  out  two  concavities  in  the  limbs,  as  indi- 
cated by  the  dotted  lines,  to  a circle  of  4^  inches  diam- 


Field  Magnet  Ready  for 

Fig.  249.  Field  Magnet.  Armature. 

eter.  The  center  of  the  circle  of  which  the  concave  sur- 
faces form  arcs  must  be  5^  inches  from  the  short  part 
of  the  U,  known  as  the  magnet  yoke,  and  exactly  mid- 
way between  the  magnet  limbs,  so  that  an  equal  amount 
will  be  cut  out  of  each  limb.  This  cutting  can  be  done 
by  any  blacksmith,  as  it  does  not  need  to  be  precise  in 
the  matter  of  the  surfaces  of  the  concavities,  the  only 
object  being  to  remove  the  bulk  of  metal  that  is  to  be 
cut  away  in  order  to  form  the  armature  chamber. 

Next  smooth  up  the  sides  of  the  magnet  on  the  flat  of 
an  emery  wheel,  rounding  off  the  corners  so  that  a face 


280 


IIOMK  MI^X'TIAXICS  FOIt  AM A'l’KUIfS 


view  of  (lie  ends  of  fli(‘  limbs  will  be  as  shown  in  Fif^. 
254;  the  faees,  f,  f,  sbonbl  also  be  snioodied  off  with  the 
(Miiery  wheel,  as  tliesi'  foi-ni  (be  base  of  (be  niacbine. 
Then  bolt  the  nia<>net  to  the  fae(“-]ilate  of  tin*  lathe  so 
that  the  center  of  the  circle,  a,  to  wliicli  tla*  niafiin-t 
limbs  wei-e  cnt  away  coinciib's  with  the  lathe  centers, 
and  bore  out  the  armature  chamber  to  4^  inches  in 
diameter,  leavinj*  the  ma<;'n(‘t  as  shown  by  Fi_i>.  250; 
the  curved  surfaces  forniinji'  th(“  armatni-<‘  chamber  arc* 
known  as  ])oIe-fac(‘s.  If  the  siib-s  of  tlie  mai>net  (by 
“sides”  are  meant  the  ])art  facing  tin*  reader  in  Fi'is. 
248,  250,  and  253,  and  the  corresiiondiny  ])ai-t  on  the 
other  side  of  the  niaj>net)  were  not  <>round  to  a true 
parallel  on  the  emery  whe(‘l,and  asit  is  hii>hly  probable 
that  they  were  not,  it  is  advisable  to  take  a sliiiht  cut 
over  the  whole  side  exjwsed  while  the  ma'iuet  is  on  the 
face-plate  so  as  to  have  it  perfectly  plane,  and  also  take 
a cut  over  the  opposite  side  to  insure  parallelism. 

The  journal  ^mkes  and  boxes  come  next.  There  will 
be  two  bearings  and  yokes,  one  for  each  side  of  the 
machine.  Fig.  251  shoAvs  the  parts  necessary  for  one 
yoke  and  bearing;  //,  y are  brass  strips  6f  inches  long, 
1 inch  wide,  and  t\  inch  thick,  with  rounded  ends;  5 
is  the  box,  made  of  a piece  of  round  brass  rod  1 inch 
in  di.imeter  and  2 inches  long  over  all,  one  end  being 
tui-ned  down  to  f inch  diameter  for  a distance  of  f 
inch,  a j|-iTich  hole  being  drilled  through  the  center 
ami  a i-itich  hole  being  drilled  in  one  side  far  enough 
1o  h‘t  the  point  of  llu'  drill  through  into  the  bore  of 
(he  box;  c is  tin*  oil  r(‘S(‘rvoir,  coiisisting  of  a piece  of 
biass  (ubing  1 inch  long,  inch  in  diamet(‘r  outside 
and  ij  inch  diamebu-  inside,  with  oiu'  end  i)ermanently 
sto|)j»cd  by  a itlug  sold(‘r<*d  in  and  the  other  end 


HOME  MECHANICS  FOE  AJIATETJES 


281 


Hireadecl  for  a distance  of  inch.  The  hole  in  the 
side  of  the  box,  h,  is  threaded  to  match  the  thread  on 
the  end  of  the  tube,  c,  which  is  packed  Avith  lamp 
wick,  filled  with  oil,  and  screwed  in  the  box  when  the 
machine  is  completed  and  ready  to  rnn.  The  yoke 
strips,  ,?/,  ;?/,  haA’e  each  a ^-inch  hole  drilled  exactly  in 
the  center,  seA’eral  nicks  being  filed  in  the  edges  of 
these  holes.  Before  putting  the  yoke  together,  tin  the 
edges  of  these  central  holes  and  tin  the  small  end  of 


o 


o 


Fig.  251. 


Fig.  252. 
Parts  of  Yoke. 


Fig.  253. 

Placing  Yokes  in 
Position. 


Magnet  with  Yokes. 


the  box,  h;  then  mount  the  strips  on  the  end  of  the 
box  so  they  will  be  at  right  angles  with  each  other  and 
so  that  the  hole  in  the  side  of  the  box  comes  between 
two  of  the  legs  formed  by  the  strips,  and  solder  the 
whole  at  the  center.  Be  sure  to  fill  the  nicks  in  the 
edges  of  the  holes  with  solder. 

When  both  yokes  liaA’e  been  assembled,  turn  up  a 
block  of  wood  II  inches  thick  to  fit  closely  the  armature 
chamber  in  the  magnet  limbs  without  spreading  the 


282 


HOME  MECTTAXICS  EOE  A:\IATKUHS 


latter.  Tliis  block  should  hav(‘ a i^-iiieh  hob*  in  tin*  (‘(‘ii- 
ter^  and  it  will  b(^  Ixdtia*  to  di  ill  IIk^  hob^  fii'st,  mount 
th(^  l)lo(*k  on  a i]-in(*h  inandr(‘l  and  tnim  it  np  lian*  with 
the  (-eiitral  hob\  IMit  this  block  in  tin*  aianatiiix*  cham- 
ber Avith  its  g-incdi  mandixd  in  tin*  ('(*nti‘al  hob*,  thi'(*ad 
one  yok(^  on  om^  (md  of  the  mandrid  and  the  oth(*r  on  tin* 
other  end,  tnrniniij  the  l(‘i>s  of  each  yok(^  to  tlu^  position 
shown  by  V\<^.  253.  riainj)  the  Avhob‘  to,2,(‘th(‘i*  scxaiixdy 
and  drill  four  :|-inch  holes,  //,  h,  //,  //,  through  the  mag- 
net limbs  and  both  yokes ; ])nnch-mark  om^  yok(^  and  tln^ 
fa(‘e  of  the  mai^net  limb  on  whi(*h  it  r(‘sts  so  that  in 
reassemblini^  the  machine  the  yarions  ])arts  will  (‘ome 
back  to  the  ori,i>inal  position  in  Avhich  th(‘y  w(‘r(^  drilled ; 
tlien  take  off  the  clamps  and  take  off  the  yokels,  r(*moye 
the  yokes  and  wooden  block  and  anneal  the  maii^net  by 
heating  it  to  a l)right  red  and  allowing  the  fire  to  die 
ont  Ayith  the  iron  coyered  np  in  the  coals. 

For  monnting  the  yokes  permanently  on  the  magnet, 
four  steel  machine  scre^ys  and  eight  distance  pieces 
Ayill  l)e  required.  The  scre^ys  are  j inch  in  diameter 
and  0:1  inches  long  under  the  head,  and  the  head 
should  be  slotted.  The  distance  pieces  to  hold  the 
yokels  away  from  the  magnet  are  made  from  round 
l)i'ass  rod  1 imdi  in  diameter;  two  of  them  are  inches 
long,  two  are  If  inches  long,  two  are  2^  inches  long, 
and  the  remaining  two  are  2f  inches  long.  Fig.  254 
shows  one  yoke  mounted,  Avith  its  distance  pieces,  c’, 
cq  and  .s*,  -s,  r(q)resent  the  thread  ends  of  the 

scr(*ws.  Tin*  yok(‘s  should  b(^  carcdully  fitted  or  trouble 
may  i‘(*snlt  from  non-alignment  of  the  Ix^arings. 

Tin.*  aianatni'c^  strinduix^  comes  mwt  hh'om  some 
d(*ab*r  in  annatni'C  stam])ings  ])ro(‘nr(^  one  hundred 
1‘ings  of  charcoal  iron  4 inches  in  <liameter  outside  and 


HOME  MECHANICS  FOR  AMATEURS 


283 


3 inches  in  diameter  inside.  These  rings  mnst  not  be 
over  jV  inch  thick  and  preferably  about  Vt  int-li  thick. 
Not  all  of  the  one  hundred  will  be  needed,  but  many 
will  be  spoiled  in  drilling.  From  a dealer  in  electrical 
supplies  procure  two  rings  of  vulcanized  fiber,  the 
same  diameter  outside  and  inside  as  the  iron  rings, and 
I inch  thick.  On  the  face  of  one  ring  space  off  twelve 
equidistant  points  on  a circle  scribed  around  the  cen- 
ter of  the  ring's  face  midway  between  edges,  as  shown 
by  Fig.  255,  in  which  the  points  are  indicated  by 


Fig.  255. 


Fig.  256. 


Fig.  257. 


Laying  Out  the 
Armature. 


Brass  Disks. 


Position  of  Holes 
for  Boits. 


A IML^  

Fig.  258.  A Trapezoid.  Fig.  269.  Tie  Rod. 

c,  c,  g,  c,  c,  g..  e,  c,  g,  e,  e,  g,  those  marked  g being  90  de- 
grees apart.  Take  two  brass  disks  4 incbes  in  diam- 
eter inch  thick,  with  a ^-inch  boss  If  inches  in  diam- 
eter on  one  side,  as  shown  by  Fig.  250,  which  may  be 
obtained  from  any  model  making  establishment,  and 
drill  through  the  center  a -f-inch  hole,  indicated  by 
dotted  line  in  the  sketch.  Clamp  on  the  smooth  side 
of  one  of  these  disks  the  fiber  ring  that  has  been  scribed, 
letting  the  marked  face  come  uppermost,  and  drill 
four  f-inch  holes  at  the  points  marked  g,  g,  g,  g,  on  the 


284 


1 1 OM  K M K(  4 1 AN  I ( K( ) A M .VV Ki: \{H 


ra(*(‘  of  file  (ln'()UiL>li  bolli  ili(‘  rini;  and  llu‘  brass 

disk.  Next  inoniit  on  a !|-in(‘li  inandKd  a block  of 
wood  2|  in(‘h(\s  tlii(‘k  and  lar!L;(^  (Mion<»li  to  |)(*rinit  tniai- 
in<>  if  down  to  a rolka*  2 inches  in  diani(d(a';  instc^ad  of 
tnrniiif;  it  to  nK^asiircincnt,  liowcvcr,  inak(‘  it  tit  snniL»iy 
into  tlie  intiador  of  the  iron  and  fibi'("  i inus.  Wdnai  tliis 
l)lo(‘k  is  tnriKMl  to  siz(^^  tlirc^ad  on  oik*  (*nd  of  tin*  niandrc*! 
tlie  1)1  ass  disk  that  has  only  a (‘(nilral  hob*,  n(*xt  ])nt  tin* 
nninark(*d  fiber  disk  on  tin*  wood(*n  bhx'k,  down  to  tln^ 
brass  disk,  and  follow  Avith  flu*  ii'on  rin^s,  ])nttin!L»  on 
last  the  fiber  rin:L>  that  lias  b(*(*n  drill(*d  and  th(*n  thr(*ad- 
in^  on  tlie  mandrel  the  brass  disk  that  Avas  also  drill(*d 
Avith  the  fiber  disk.  Turn  the  disk  so  that  tin*  hol(*s 
near  its  edf>e  ai»T(*e  AAitli  those*  in  the  fib(*r  rini^-  under 
it  and  compress  the  Avhole  arran<>enient  Avith  clam])S. 
If  there  are  so  many  iron  disks  that  the  fiber  riiyi;’ 
cannot  be  draAvn  doAA  n oy(*r  the  end  of  the  aa ooden  cen- 
tering’ block,  take  off  enough  to  let  this  lx*  dom*,  as  it 
is  imperatiA^e  that  all  the  ring’s  and  disks  should  be 
accurately  centered  aa  itli  each  other.  Then  drill  }-inch 
holes  throni>li  the  Avliole  mass,  entering’  the  drill  in  the 
holes  already  bored  in  the  top  brass  disk  and  fiber  ring. 
These  four  |-inch  holes  are  for  tie-bolts  to  hold  the 
armature  core  together. 

AVhen  the  drilling  is  finished,  punch-mark  each  brass 
disk  and  fiber  ring  near  one  of  the  |-inch  holes  (the 
saiiK*  OIK*  in  (*a(‘h  (‘as(*,  of  course*),  remoAX*  the  (damps 
and  1h(*  bi'ass  and  fib(*i‘  ])i(*C(*s,  run  a wire  through  the 
hob*  in  the*  iixin  rings  (*orr(*S])onding'  to  the  one  marked 
on  11k*  fib(*i‘s  and  disks  and  tic*  th(*ni  b)os(*ly  together 
nniil  lime*  1o  ass(*mbl(*  IIk*  c'orc*.  Th(*n  cdani])  the  tAVO 
1ib(*r  rings  1og(*lh(*i*,  wdlh  IIk*  mark(*d  hob*s  in  align- 
nK*nt,  and  di*ill  Ihrongh  both  idngs  a iV  iaeh  hole  at 


HOME  MECHANICS  FOE  AMATEUES 


285 


each  point  marked  c,  leaving  each  ring  as  shown  by 
Fig.  257. 

Ne.xt  cnt  out  of  hard  wood  tw'enty-fonr  trapezoidal 
blocks  (Fig.  258)  f inch  thick,  f inch  wide  at  one  end, 
-J  inch  wide  at  the  other,  and  i inch  long.  In  the 
center  of  sixteen  of  these  drill  a iV  inch  hole;  in  the 
center  of  the  other  eight  drill  a :|-inch  hole.  Fin  the 
sixteen  trapezoids  having  small  holes  to  the  faces  of 
the  two  fiber  rings,  patting  the  pins  throngh  from  the 
back  throngh  the  tV  inch  holes  in  tlie  rings;  the  pins, 
which  must  be  of  brass,  should  be  a tight  driving  fit  so 
that  the  trapezoids  will  not  tend  to  slip  off,  and  the 
faces  of  the  latter  should  be  coated  with  shellac  varnish 
to  prevent  their  turning  on  the  pins. 

The  tie-holts,  mentioned  above,  are  of  brass,  fV  inch 
in  diameter  and  3f  inches  long,  threaded  at  each  end 
for  a distance  of  tV  inch.  They  mast  he  insulated  where 
they  pass  throngh  the  core  by  wrapping  paper  on 
them,  gluing  each  layer  and  putting  on  enough  to 
make  the  insulated  portion  fit  sniigly  in  the  :{;-inch  holes 
drilled  through  the  rings.  Cut  a strip  of  manila  paper 
2|  inches  wide  and  wrap  it  tightly  on  the  bolt,  leaving 
an  equal  length  of  uncovered  metal  at  each  end.  When 
the  right  thickness  of  insulation  is  obtained,  drill  two 

inch  holes  in  the  holt,  exactly  2iV  inches  from  center 
to  center,  and  equal  distances  from  each  end  (this  dis- 
tance, if  the  holt  has  been  accurately  cut  to  the  length 
specified,  will,  of  course,  be  ||  inch).  Two  nuts  must 
he  also  provided  for  each  holt,  and  two  steel  pins  which 
are  driving  fits  in  the inch  holes,and  slightly  tapered. 
One  of  these  tie-rods,  without  its  nuts  and  pins,  is 
shown  by  Fig.  259. 

Then  assemble  the  armature  core  on  its  wooden  cen- 


286 


irOMK  MECHANICS  FOE  A:\IATEUES 


terin^  bloc'F^  (‘iioii^li  iron  disks  to  immIo*  tlio  iron 

])art  iiieasiire  1]  iiudu^s  in  tliirkn(‘ss  wlnai  (*oni])r(‘ss(‘d 
and  beinj>'  earofnl  to  liave  tlioso  of  tlie  j-incli  liol(*s  tliat 
were  marked  on  tlie  fibre  ])i(M‘es  (‘oine  in  lim^  witli  the 
liole  tlironi>’b  wbicdi  tlu^  wir(‘  lioldinii;  tli(‘  iron  disks 
toi>'etlier  was  rnn.  L(^av(‘  olT  11i(‘  brass  disks  for  tlie 
])resent.  Tlii*oni>li  each  J-iindi  bol(‘  ])nt  a ti(*-]'od,  elainp- 
inji^  tbe  strnetnre  until  tln^  st(‘(‘l  ])ins  can  I)(»  i)nt  in  tlie 
holes  in  the  tie-rods;  enoni>h  iron  disks  slionld  lx*  jmt 
in  to  prevent  any  looseness  when  the  (damps  are  rc*- 
moved.  Fig.  2G0  sIioavs  the  complete  structure.  After 


Fig.  260.  Fig.  261.  Fig.  262. 

Armature  Ready  for  The  Slitted  Tube  for  Commutator. 

Winding. 


the  ti(*-rods  are  pinned  in  place  the  remaining  trape- 
zoids are  put  on  over  the  ends  of  the  rods;  a little 
groove  will  have  to  be  cut  in  the  back  of  the  trapezoid 
to  accommodate  the  steed  j)in  in  the  end  of  the  tie-rod. 

Tin*  (‘ommutator  com(*s  next,  and  while  it  would  be 
advisable*  to  buy  a com])l(*te  commutator,  a very  serv- 
i(‘(*abl(*  OIK*  (*an  lx*  made  with  ])roper  care  in  following 
out  1h(*  instructions  giv(*n.  If  the  build(*r  prefers  to 
buy  ih(*  comimitatoi',  1h(*  dim(*nsions  a(‘(X)m])anying  the 
ord(*r  must  lx*  Mi(‘S(‘:  I)iam(*t(*r  of  brush  surface,  1 
imdi;  l(*ngth  along  tin*  shaft,  11“  inches;  number  of 


HOME  MECHANICS  FOR  AMATEURS  287 


segments,  12.  If  the  commiHator  is  to  be  built  along 
with  the  rest  of  the  machine,  proceed  as  follows : 

Take  a piece  of  brass  tubing,  1 inch  in  diameter  out- 
side, with  a wall  about  ^ inch  thick,  and  measuring 
21  inches  long.  Slit  it  at  twelve  equidistant  points 
for  a distance  of  11  inches  from  one  end,  as  shown  by 
l^bg.  261,  and  insert  the  unslitted  portion  in  a hole  in  a 
block  of  wood  that  just  fits  the  tubing;  the  block 
should  be  1 inch  thick  and  nailed  to  a bench  or  other 
support.  Then  bend  outwardly  the  narrow  strips  made 
by  slitting  the  tubing  until  it  looks  like  Fig.  263 ; the 
wings  shonld  be  brought  to  a right  angle  with  the  body 
of  the  tubing  not  slitted,  and  hammered  out  fiat. 
Number  the  “wings”  by  means  of  punch  marks,  from 
one  up  to  twelve,  and  then  carry  the  slits  along  the 
length  of  the  uncut  portion  of  the  tube,  cutting  it  up 
into  twelve  pieces  like  Fi<r.  264.  Next  turn  up  two 
rings  of  vulcanized  fiber  2 inches  in  diameter  outside, 
1 inch  in  diameter  inside  and  1 inch  thick,  and  fit 
around  the  circumference  of  each  twelve  steel  screws, 
1 inch  in  diameter  and  f inch  long  over  all,  without 
heads,  as  shown  by  Fig.  265,  the  screw-holes  being  car- 
ried clear  through  so  that  the  point  of  the  screw  may 
emerge  on  the  inside  of  the  ring.  Fut  thirty-six  strips 
of  oil  paper  (the  kind  used  with  copying  books  to  pro- 
tect the  leaves  from  moisture)  inch  thick,  inch 
wide,  and  14  inches  long.  Assemble  the  pieces  of  the 
commutator  in  numerical  order  within  the  two  fiber 
rings,  one  ring  at  the  wing  end  and  one  at  the  other 
end  of  the  tubular  part,  put  three  slips  of  oil  paper  be- 
tween each  pair  of  neighboring  pieces  of  tube,  and 
draw  the  segments  toward  the  center  by  means  of  the 
little  screws  until  the  oil  paper  slips  are  clamped  so 


288  llOMK  MI^](MI  AN  K^S  KOI?  AMATKU1?S 


tij»litly  between  tlu^  brass  s(\i>iiu‘nts  tliat  tluw  cannot  b(‘ 
])nlI(Hl  out  with  tli(‘  iin^(*rs.  In  ordca'  to  liav(‘  tin*  coni- 
nintator  come  toi»(Mli(‘r  and  foian  an  ai)])roxiiMat(*ly 
true  (drcle,  a saw  blad(‘  3^^  iin-lj  tliick  slionld  b(‘  ns(*d  in 
cnttini*  tlH‘  sei»in(mts  ont  of  tlie  tube.  Tlien  l)y  jiidi- 


Commutator  Tube  Before  it  is 
Cut  into  Segments. 


Fig.  265. 

Fiber  Ring  with  Screws. 


Fig.  264.  One  Segment. 


Fig.  266. 

The  Commutator. 


cions  s(ddin^  np  on  tlie  screws  the  surface  can  be 
liron^lit  suftici(mtly  m^ar  to  a true  (drcle  as  to  recpiire 
no  truing  nj)  \u  tin*  latli(‘.  The  ])rotrudin<»  edf>es  of 
tin*  oil-jiapiu'  sli])S  can  b(^  cut  off  (‘vcm  witli  tlie  brass 
witli  a sliai'|)  knife. 

Tin*  (‘or(*  of  tin?  commutator  may  bo  mad(i  of  wood; 


HOME  MECHANICS  FOR  AMATEURS 


289 


mount  a block  on  a f-incli  mandrel  and  turn  it  up  to 
the  exact  diameter  of  the  interior  of  the  commutator ; 
then  taper  it  slightly  so  that  it  will  pass  through  the 
commutator  before  binding,  and  drive  it  home  as  tight 
as  possible  without  straining  the  fiber  rings  that  hold 
the  segments.  Cut  off  the  block  ^ inch  beyond  the 
wing  end  of  the  commutator  and  flush  with  the  other 
end.  The  complete  commutator  is  shown  by  Fig.  266. 

The  next  piece  of  machine  work  is  the  shaft,  shown 
by  Fig.  267.  It  is  turned  up  from  a piece  of  |-inch  bar 
steel  10|  inches  long.  The  dimensions  are  as  follows : 
A,  I inch  diameter,  2iV  inch  long;  f inch  di- 
ameter, If  inches  long;  C,  f inch  diameter,  3|  inches 
long;  Z),  f inch  diameter,  inches  long.  Last  in  the 
list  of  machine  work  on  the  motor  proper  are  the  brush 
holders,  one  of  which  is  shown  bj^  Fig.  268,  the  drawing 
shoAving  two  views.  The  holder  is  a piece  of  brass 
tubing,  f inch  internal  diameter  and  If  inches  long, 
mounted  on  a piece  of  strip  brass  f inch  wide  and  A 
inch  thick,  the  other  end  of  which  is  bent  into  a loop, 
as  shown,  and  provided  with  an  insulating  bushing,  t, 
of  tV  inch  fiber.  The  internal  diameter  of  the  bushing 
is  a trifle  over  an  inch  when  the  clamping  screw  is 
loose,  and  the  diameter  of  the  loop  in  the  brass  strip  is, 
therefore.  If  inch  maximum.  This  loop  is  intended  to 
fit  around  one  of  the  distance  pieces,  0,  Fig.  254,  from 
which  it  is  insulated  bv  the  bushing,  t. 

The  brush  is  a piece  of  round  carbon,  f inch  in  di- 
ameter and  1 inch  long;  it  should  fit  snugly  within  the 
tube  forming  the  holder,  and  a spiral  spring,  f inch 
in  diameter,  made  of  No.  16  brass  wire,  must  be  pro- 
vided to  force  tbe  brush  outwardly  on  to  the  com- 
mutator. One  brush  holder  is  attached  to  the  lower 


290  TIOMF.  MFCJIAXirS  FOR  A:\IATFIIRS 


left-liand  (listaiic*e-])io(‘(‘,  c,  and  lln^  ollua*  to  tli(‘  ii])])(*r 
rii»ld-liand  ])i(M‘05  tlio  tnl)nlai'  ])ai'f  of  tli(‘  liold(‘r  s(*l- 
tiiig  Yoi'ti('all y,  Ixdwoini  tln^  inai»ii(*t  ])oI(‘s,  witli  its  in- 
011(1  not  niorc^  tlian  J iiK'li  from  tin*  snrfa('(‘  of  tin* 
('oininntator.  F]l(H‘tri(‘al  ('oniKH'tion  is  niad(‘  witli  Wni 
lirnsli  arm  by  moans  of  a ])ioo(*  of  tl(‘xil)l(‘  (‘oi'd,  snoli 
as  is  nsod  in  ]iani»’ini>  in('and(‘S(‘(mt  lamjis,  on(‘  (md  of 
tlio  (‘ord  l)oini>‘  soldcnxMl  to  a (‘0])])(n‘  waslior,  wliicdi  is 
olaniiiod  nndcn'  tlio  lioad  of  tlio  sorc^w  on  tli(‘  brnsli  arm. 
This  cord  is  known  as  No.  IS  (‘otton-c'ovorod  la.mp- 
cord,  and  may  bo  jirocnrod  from  any  d(‘alor.  It  slionld 
bo  nntwistod  and  ono  loni>tli  iiscmI  on  (^acli  lirnsli  lioldor; 
tlio  cord  nood  not  bo  mor(^  tlian  (>  inclu^s  lon<>\ 

Wo  aro  noAv  roady  to  wind  tlio  nia<>not  and  armatnro 
coros.  Tho  armatnro  coro  iiinst  first  lio  covorc^d  all 
around  tlio  ontsido  snrfaco  with  innslin;  cut  a strip  2 
inches  wide  and  25  inches  lon^  and,  after  varnishiiy^ 
tho  porijihory  of  the  coro  with  shellac,  Avind  on  this 
muslin  strip,  being  sure  that  it  is  tightly  wound.  If  it 
is  iinlled  tight,  it  Avill  make  two  layers;  Avhen  the 
strip  has  been  carried  once  around,  A^arnish  the  surface 
of  Avhat  is  on  the  core,  and  then  Avind  on  the  other 
layer  of  innslin.  Then  Amrnish  the  AAhole  outside  sur- 
faces Cut  out  24  strips  of  oil  paper,  each  ItV  inches 
Avid(^  and  2 inches  long,  and  bend  np  the  edges,  making 
th(^  cr(sis(^  j inch  from  (sicli  edge,  so  as  to  form  shalloAA^ 
troughs  th(‘  Avidth  of  AAliich  aaoII  bo  tho  same  as  the 
S])a(‘(‘  l)(dw(Mm  lln^  trapezoids  on  tho  end  of  the  coro; 
apply  tAvo  of  tho  troughs  to  tho  inside  and  ontsido 
oirch^s  of  th(‘  cor(‘,  as  shoAAm  in  Ffig.  270,  and  tie  tlumi  in 
])lac(*  AA'illi  No.  40  or  No.  50  soAving  (‘otton,  ono  strand 
at  (sioli  sid(‘  of  th(‘  1 rough.  Them  Avind  on  an  old  (‘ot- 
ton-spool  08  f(*(‘t  of  No.  20  double  cotton-covered  mag- 


HOME  MECHANICS  FOE  AMATEUES 


291 


net  wire,  hook  the  outer  end  around  one  trapezoid,  as 
in  Fig.  271,  and  wind  into  the  wiring  space  between 
this  trapezoid  and  its  right-hand  neighbor  a coil  the 
full  width  of  the  space,  which  should  take  2G  turns  in 


c 


3 


Pig.  267.  The  Shaft. 

width,  putting  five  laj^ers  in,  or  130  turns,  to  each  coil. 
When  the  first  coil  is  done  twist  to  the  final  end  the 
beginning  end  of  the  wire  which  is  to  Aviud  the  next 
coil,  and  proceed  with  that  one  in  the  same  way.  Care 
must  be  observed  to  put  exactly  the  same  number  of 
turns  in  each  coil  and  to  twist  the  ending  of  each  coil 
to  the  beginning  of  its  neighbor  on  the  right.  When 
the  armature  is  wound,  put  on  the  brass  disks  that 
were  left  off  when  the  core  was  assembled,  threading 
the  tie-rods  through  the  holes  near  the  edges  of  the 


Figs.  268  and  269.  Fig.  270.  Pig.  271. 

Brush  Holders.  Section  Prepared  for  Beginning  the 

Winding.  Winding. 


disks,  and  putting  the  boss  on  each  disk  outside;  clamp 
the  disks  hard  against  the  wooden  trapezoids  Iw  means 
of  nuts  on  the  tie-rods.  The  holes  in  the  disks  must 
be  bushed  with  little  pieces  of  fiber  tubing  and  a fiber 


m HOME  MECHANICS  EO]{  AMA'I’ETIHS 


wjislioi'  iiinst  uiHl(!r  (‘acli  luit,  in  or<l(“i‘  to  insulate; 
the  tie-rods  from  tin*  disks;  otherwise*  the*  armature; 
wemlel  run  elestrne  tively  heet. 

Insert  the  slmft  in  the  e‘e‘nter  eef  the  structure*,  ledtinj^ 
that  part  marke'd  71  in  Fi,u;.  2t)7  e;ome  een  tlie  siele  wliere* 
the  ends  of  tlie  armature*  wijidim*-  are,  and  ])in  the 
brass  disks  tee  the  slmft  thi'eeiyuh  the  be^sse's.  The*  e*e)m- 
mutateer  ”oes  een  the*  ])ai*t  e)f  the  shaft  just  referre*el  tee, 
anel  it  shonlel  be  a elrivinj;  fit,  see  as  to  eebviate*  leinnin*' 
en*  keying  it  to  the*  shaft.  The*n  ceninect  up  the  enels 
e)f  the  armature  coils  tee  the  lugs  e)f  the  commutator, 
le>adiug  eaedi  enel  straight  eeut,  jearalle*!  with  the  shaft, 
to  the  nearest  lug.  If  the  ends  were  twisteel  teegether 
in  accordauce  with  the  directieeus,  the  result  will  be 
as  shown  eliagrammatically  by  Fig.  272. 

Prepare  for  wineling  the  magnet  coils  by  making  a 
winding  bobbin  as  follows : On  a piece  of  board  an 
inch  thick  and  4 inches  square  lay  out  a square  meas- 
uring If  inches  on  a side,  the  scribed  square  being 
symmetrical  with  the  edges  of  the  board;  clamp  an- 
other similar  piece  of  board  to  the  one  marked,  and  at 
the  corners  of  the  scribed  square  drill  f-incli  holes 
through  both  boards;  in  the  center  of  the  square  drill 
a -|-inch  hole.  Then  make  a mandrel  of  4-inch  round 
iron,  the  central  part  being  full  diameter  and  24 
inches  long,  and  the  ends  being  turned  down  to  pass 
through  the  central  hole  in  the  board.  Moiint  the 
boards  on  the  (*nds  of  the  mandrel  and  run  f-incli  iron 
rods  through  the  corner  holes,  forming  a sort  of  reel, 
as  shown  by  Fig.  273.  Jam  the  boards  against  the 
should(*rs  of  tin*  mandrel  by  means  of  lathe  dogs  on 
the  outer  (*uds  of  flu*  latter,  and  drive  a nail  in  the 
face  of  each  board  so  that  the  dog  will  drive  the  board 


HOME  MECHANICS  FOE  AMATEURS 


393 


without  slip.  The  dogs  must  be  so  adjusted,  of  course, 
as  to  drive  both  boards  in  their  proper  angular  posi- 
tions, maintaining  the  parallelism  between  the  ^-inch 
rods  and  the  mandrel  that  is  necessary  to  form  a per- 
fect coil. 

Mount  this  winding  frame  in  the  lathe  and  wind  a 
coil  on  it  of  No.  21  double  cotton-covered  magnet  wire, 
putting  as  many  turns  as  possible  (it  should  take  sixty- 
six)  between  the  faces  of  the  wooden  blocks  and  mak- 
ing the  coil  twenty-seven  layers  deep.  The  starting 
end  may  be  secured  to  the  projecting  end  of  one  of  the 
•|-iuch  rods  to  give  the  necessary  tension  to  the  first 


Fig.  272. 
The  Winding. 


Fig.  273. 

Reel  for  Winding  Field 
Magnet  Coils. 


layer  of  wire,  and  at  least  a foot  of  the  starting  end 
should  be  left  free.  When  the  coil  is  finished,  tie  it  at 
each  of  the  four  corners  with  strong  linen  thread, 
bending  the  final  end  sharply  backward  over  one  of 
these  corner  threads  to  keep  the  top  layer  snug;  take 
the  winding  frame  apart  and  varnish  the  coil  all  over 
with  shellac,  setting  it  aside  to  dry  while  the  second 
coil  is  wound.  This  is  exactly  like  the  one  already 
wound. 

Then  take  the  journal  yokes  and  their  bolts  and 
distance  pieces  off  the  magnet  and  wrap  the  magnet 
limbs  with  muslin  from  ^ inch  above  the  bolt  holes 
up  to  the  bend,  putting  two  layers  on  each  limb  and 


294 


HOME  I^IECHANICS  FOR  A]\TATETTHS 


\arnisliiTii»  it  on  tlie  ontsidc^  of  (*a(*li  lay(*i\  Wlien  tin's 
is  drjj  tniai  tlie  nia^iiet  n])sid(^  down,  tlii'(*ad  on  (‘a(*h 
limb  a fiber  washer  inelies  square  and  i ineli  tlii(‘k, 
tlie  hole  in  the  waslnn*  fitting  the  inai»]i(R.  limb  snn<»;ly; 
varnish  the  fa('es  of  th(^  Avashei's  now  ni)i)(nanost  ami 
slip  the  coils  on  the  limbs  down  on  the  wash(‘rs  whil(‘ 
the  varnish  is  w(d,  so  that  the  lattcn'  will  sti(‘k  to  th(‘ 
coils.  In  pnttinf>’  on  the  coils,  s(‘e  that  tln^  b(\i»innin<? 
end  of  each  coil  ^oes  on  fii'st,  so  that  wlnm  tlu^  machine 
is  set  rioht  side  np  the  final  end  of  each  coil  will  b(‘ 
nearest  the  armature.  T'ollow  (^ach  (‘oil  with  aiiotlnw 
fiber  washer  like  those  first  x)nt  on  the  magnet,  and 
then  reassemble  the  journal  yokes  and  distance  i)ie(‘es 
on  the  niaf>net,  this  time  putting  in  the  armature  as  you 
j>‘o  along  and  also  putting  on  the  brush  holders  and 
f)rushes.  Tlie  holders  should  b(‘  so  adjusted  that  the 
ends  of  the  brush  tubes  are  tV  t<>  « inch  aAvay  from  th(‘ 
surface  of  the  commutator. 

The  free  ends  of  the  magnet  coils  nearest  the  arma- 
ture are  connected  to  the  brushes  by  means  of  flexible 
lamp  cord,  as  described  in  the  instructions  for  making 
the  brush  holders,  the  end  of  the  flexible  cord  being 
soldered  to  the  end  of  the  magnet  Avire  close  up  to  the 
coil.  Th  upper  ends  of  the  magnet  coils  go  to  the  ter- 
minal blo('k,  Avhic'h  is  a block  of  Avood,  1}  inches  square 
and  4 iindn^s  long,  bolted  on  the  top  of  the  magnet 
yoke,  and  caiawing  two  binding  posts,  AAhich  form  the 
tcaaiiinals  of  th(‘  machim^  The  motor  is  bolted  to  the 
tabl(‘  of  th(‘  serving  nnudiine,  Avith  one  leg  right  on  the 
(*dg(‘  of  1h(‘  tabl(‘  and  in  such  position  that  the  pulley 
of  th(^  motor,  whi(*h  must  go  on  the  end  of  the  shaft 
away  from  1h(i  commutator,  is  in  line  Avith  the  belt 
I)idl(w  of  th(‘  machin(‘.  The  motor  pulley  should  be 


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295 


one-half  the  diameter  of  the  pulley  on  the  sewing  ma- 
chine, and  be  of  the  same  width  and  depth  of  groove. 

The  regulator  is  shown  by  Figs.  274  and  275,  the 
former  being  the  front  vie^v  and  the  latter  the  back. 
Referring  to  Fig.  274,  A is  a wooden  arm,  9^  inches 
long,  4 inch  thick,  and  tapering  from  4 inch  to  IJr  inches 
in  width.  The  narrow  end  is  faced  with  a thin  strip  of 
copper  to  make  contact  with  the  buttons,  c,  which  are 
simple  brass  bolts  with  flat  heads;  the  wide  end  of  the 
wooden  arm  is  split  to  straddle  the  shaft,  to  which  it  is 
pinned  as  well  as  clamped.  L is  the  lever  controlling 


Fio.  274. 

Regulator — Front  View. 


Fig.  275. 

Regulator — Back  View. 


the  arm,  A ; it  is  made  of  4-inch  round  iron  rod,  bent 
to  form  a right  angle;  the  lever  portion  is  G inches 
long;  the  length  of  the  horizontal  portion  on  Avhich 
the  lever.  A,  is  mounted  is  the  same  as  the  width  of 
the  sewing  machine  table  on  which  the  motor  is  to  be 
used.  The  back  end  of  the  shaft  is  journaled  in  the 
base  board,  C,  and  the  front  part  in  a wooden  bearing, 
li,  which  is  bolted  to  the  under  side  of  the  sewing  ma- 
chine table  between  the  narrow  drawer  and  the  pan. 
The  baseboard,  C,  is  0 inches  wide  (vertically)  and  IO4 
inches  long.  It  is  fastened  to  the  under  side  of  the  ma- 
chine table,  flush  with  the  back  edge.  The  lever,  E,  is 
to  be  moved  by  the  right  knee  of  the  machine  operator. 


290  HOME  MECJlAiNlCS  EOU  AMATEUKS 


The  ariiij  is  iiornially  lield  in  its  lii<»lH‘st  i)Ositi()n 
by  the  coil  spring  shown^  in  Avhi(‘li  position  tlie  (aii'rent 
is  cut  olt*  the  motor  entirely.  The  conta(*t  buttons, 
are  4 inch  in  diameter;  tlie  bolts  of  which  they  are 
tlie  liead.s  are  inch  in  diameter  and  loii”-  enou<>li  to 
protrude  | iiieli  on  the  reversi*  sid(‘  of  tlie  base  hoard. 
This  side  is  shown  hy  hM<;'.  275.  The  resistance  coils 
consist  of  Gernian  silver  wire,  No.  20  B.  and  H.  f^auj^e, 
wound  into  coils  on  a f-inch  rod  (the  rod  heinj^  re- 
moved, of  course,  when  the  coil  is  formed).  The  jiii'ce 
of  wire  forming  the  niiper  coil  should  he  100  feet  long; 
the  next  coils  contain  90,  80,  70,  00  and  50  feet  of  wire, 
resi)ectively,  in  the  order  named.  The  binding  posts, 
7\  and  7\,  are  connected  as  shown,  the  connection  be- 
tween 7'i  and  the  iron  shaft  being  made  bj'  means  of 
flexible  cord  which  will  follow  the  movements  of  the 
shaft.  On  the  front  the  shaft  is  connected  to  the  cop- 
per facing  at  the  small  end  of  the  arm,  .1,  by  means  of 
No.  10  copper  wire.  All  the  connections  on  the  back 
are  made  with  No.  10  copper  wire,  preferably  but  not 
necessarily  insulated. 

The  back  surface  of  the  base  board  must  be  covered 
Avith  a sheet  of  asbestos  over  a thin  sheet  of  fiber.  The 
ends  of  the  resistance  coils  are  tAvisted  together  and 
soldered,  and  the  connecting  Avires  should  be  soldered 
on  at  the  same  time.  The  coils  are  held  on  ordinary 
poi'celain  knobs,  fastened  to  the  board  by  Avood  screAA’S. 
Th(!  coniK'cting  Avires  should  be  bent  into  loops  Avhei’e 
they  coniK'ct  Avilh  the  bolts,  c,  and  a copper  AA’asher 
shoidd  go  under  each  nnt  and  on  top  of  the  loop  of  the 
connccling  Avire. 

Th(*  conneclions  betw(‘(‘n  Ihe  motor  and  the  regulator 
and  the  source  of  curreut  sui)2)ly  are  as  follows:  From 


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297 


Ti  to  one  binding  post  on  the  motor,  from  to  one  side 
of  the  supply  circuit,  and  from  the  other  binding  post 
on  the  motor  to  the  other  side  of  the  supply  circuit. 

The  motor  above  described  will  run  satisfactorily  on 
any  direct-current  incandescent  lamp-circuit  of  100  to 
120  volts  pressure.  If  it  is  desired  to  build  the  ma- 
chine for  use  in  connection  with  a batterj^,  the  Avindings 
Avill  have  to  be  changed  as  follows : Armature  coils. 
No.  13  wire,  8 turns  wide  and  1 deep,  each  coil;  field 
magnet  coils.  No.  8 Avire,  5 layers  deep,  18  turns  per 
layer,  each  coil;  regular.  No.  13  Avire,  the  coils  having 
one-tenth  the  number  of  feet  specified  aboA'e. 

The  battery  to  run  such  a motor  must  giA^e  8 volts 
and  from  10  to  20  amperes,  according  to  the  load  on  the 
motor;  consequently  four  cells  Avill  be  required. 

Should  the  reader  desire  to  build  a standard  shunt- 
Avound  motor  of  i horse  power  instead  of  the  series- 
Avound  type  specified,  the  same  frame  may  be  used, 
the  only  variation  being  in  the  manner  of  Avindiug. 
In  order  to  Avind  the  machine  as  a i horse  power  mo- 
tor, to  AA’ork  on  a 110  Amlt  circuit,  the  armature  coils 
must  consist  of  No.  27  Avire,  double  cotton-covered, 
each  coil  being  9 layers  deep  and  28  turns  in  width — 
252  turns,  total,  per  coil.  The  magnet  coils  Avill  con- 
sist of  No.  25  Avire  wound  to  a depth  of  39  layers,  with 
as  many  turns  lengtliAvise  as  can  be  got  in  the  space  of 
2|  inches  allotted  for  the  coil  length;  Avith  careful 
Avinding,  92  turns  can  be  put  in  each  layer,  giving  each 
magnet  coil  a total  of  3,588  turns. 

In  order  to  change  the  design  into  a | horse  power 
motor,  the  magnet  must  be  made  of  iron  2|  inches 
square,  instead  of  1^  inches,  and  the  armature,  shaft, 
journal-yoke  bolts,  etc.,  must  be  made  exactly  1 inch 


ucnih]  IMKC'lIAxYirS  KOI?  AMA^I’Ki;i?S 


20<S 


l()iif»(‘r,  axially,  tliaii  tlu^  al)()V(‘  iii(*asni'(*iii(*iils  s|)(‘cify. 
The  wiiidiiii^s  will  1)(‘  No.  24  wire  on  th(‘  ariiiatni'(‘,  (*ach 
(‘oil  5 layers  (1(M‘])  and  21  turns  wid(*;  No.  22  wii'(‘  on  tli(‘ 
inai>net,  ea(4i  (‘oil  l)(4niL»  .‘>7  laycas  d(*(*])  and  74  turns 
lonj»*  (or  as  many  as  the  24  inch  si)a(‘(‘  will  tak(7). 
The  nninlxa'  of  armature  (‘oils  and  all  ()th(a‘  data  not 
s])(H‘iticHl  in  this  ])ara,i>ra])h  Avill  remain  ])re(‘is(4y  as  in 
the  original  instructions  al)()V(\ 


A DESIGN  Foil  AN  ELECTKir  LAUNCH  :\IOTOK 

For  the  propulsion  of  an  ele(‘tri(‘  lann(‘h  a motor 
must  unite  elements  of  efh(‘ien(‘y,  (‘()mpa(‘tn(^ss,  and 
strength  to  a d(\gree  scar(‘(4y  iie(‘(^ssary  in  any  other 
situation.  The  design  given  luwe  is  for  a motor  of  un- 
usual simplicity  of  construction,  Avhi(‘li  (‘an  (aisily  be 
built  by  ail  amateur  at  small  (‘ost.  It  is  intended  for 
a boat  of  about  24  feet  over  all  and  4 feet  b in(‘hes 
Ixnim,  drawing  18  inches,  and  is  capable  of  propelling 
such  a (‘raft  at  a speed  of  7 miles  per  hour.  Gearing  of 
all  sorts  has  been  dispensed  Avith,  the  motor  being 
a(la])t(xl  for  direct  attachment  to  the  propeller  shaft. 
AAdiile  the  description  below  refers  primarily  to  a motor 
for  a (‘raft  of  this  size,  dimensions  are  also  given  for 
the  (‘onstru(‘ti()n  of  motors  for  smaller  launches. 

Without  going  into  the  details  of  (‘alciilation,  it  may 
b(*  slabxl  lhat  for  su(‘h  a l)()at  the  most  effi(‘ient  service 
will  b(‘  had  fi‘()m  a four-bla(l(Ml  s(‘r(^w,  about  14  inches 
in  diani(4(U‘,  12  in(‘h(*s  ])il(‘h,  Mo  p(M‘  (‘(uit.  bbuh^  area 
(by  whi(‘h  is  m(‘ant  with  blad(‘s  having  a toLil  ])r()je(‘t- 
ed  ar(^a  (‘(pial  1o  ‘>5  jx^r  (‘(uit.  of  that  of  a 14-in(‘h  disk). 


HOME  MECHANICS  FOR  AMATEURS 


299 


Fig.  276.  Longitudinal  Section  of  Launch,  Showing  Interior  Arrangements. 


300 


Ji()iMi<]  MECiiAX'ics  F()i{  a:\iateijhs 


at.  880  revolul ions  ]»(‘r  niiiiuli*.  Siicli  a screw 
will  aOsorb  about  4 boi'S(!  power.  No  very  detiiiite  fig- 
ure's of  speeds  and  ])oweis  can  be*  given,  as  tiu'se  de- 
pend very  largely  u])on  the  shape  of  the  boat,  its  full- 
ness fore  and  aft,  the  luoulding  of  fhe  runs,  etc.  The 
motor  described  Ix'low  will  give*  a sjx'e'el  of  7 inib's  ])er 
hour  to  a ratlu'r  full-modeh'd  boat  of  tlu*  size  iiidicat(*d, 
when  fully  loaded  to  a dis])lac(‘nient  of  5,000  jxuinds. 
This  means,  assuming  that  the  boat  itself  weighs  about 
1,000  pounds,  a carrying  capacity  for  about  ten  or 
twelve  passengers. 

The  storage  battery  consists  of  24  elements,  arrang('d 
in  two  series  of  12  cells  each,  each  cell  being  of  about 
80  ]K)unds  weight.  These  cells  contains  13  plates  each, 
about  7J  inches  square,  and  are  about  74x84  inches 
square  by  11  inches  in  height,  these  measurements  be- 
ing outside  of  the  rubber  containing  jars.  They  should 
be  mounted  in  two  wooden  boxes,  about  84  inches 
Avide  by  14  inches  deep  inside  and  about  7 feet  6 inches 
long.  These  make  convenient  seats  in  the  boat,  and 
their  lids  mav  be  coA-ered  Avith  cushions.  Thev  should 
be  placed  side  by  side  amidships,  as  low  as  possible 
and  a little  forward  of  the  center  of  gravity  of  the  boat 
to  compensate  for  the  Aveight  of  the  motor,  AAdiich  is 
installed  Avell  aft.  Such  cells  may  be  bought  from 
any  one  of  several  Avell-knoAvn  American  makers  of 
accumulators.  Elements  in  glass  jars  should  not  be 
used,  on  account  of  the  danger  of  breakage. 

h'or  tin*  smaller  sizes  of  motor  described  beloAV,  or,  in 
(dh(*r  Avords,  for  smalb'r  boats  of  the  same  general 
lype,  ilu'  number  of  c('lls  remains  the  same,  but  their 
size  may  be  ]»r(q»oi'tioual<'ly  r(‘duc(*d.  AVith  cells  of 
the  same  type,  having  plates  of  the  size  given,  a 3 horse 


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301 


power  boat  will  require  those  having  9 plates  and  a 2 
horse  power  boat  those  having  7 plates. 

Terminals  for  charging  should  be  attached  to  the 
boxes  containing  the  cells.  It  is  by  all  odds  the  best 
plan  to  charge  the  cells  in  the  boat,  and  not  to  at- 
tempt to  remove  them  for  this  purpose. 

The  capacity  of  these  outfits  on  one  charge  is  about 
3 hours’  run  at  full  speed,  or  about  7 hours’  run  at 
about  44  miles  per  hour,  thus  giving  the  boat  in  each 
case  a cruising  radius  of  about  30  miles.  If  a larger 


Pigs.  277  and  278.  Section  of  Coupling. 


cruising  radius  is  desired,  it  may  be  attained  by  the 
use  of  larger  cells,  but,  as  these  are  heavier,  their  use 
means  a corresponding  decrease  in  the  passenger  carry- 
ing capacity  of  the  boat. 

The  motor  illustrated  herewith  is  of  a four-pole  in- 
closed type,  waterproof  and  intended  to  be  attached 
directly  to  the  screw  shaft.  Some  form  of  flexible 
coupling  is  recommended,  that  shown  in  Figs.  277  and 
278  being  very  simple  and  easily  made.  It  consists  of 
two  cast  iron  flanges,  the  larger  about  12  inches  in  dia- 
meter for  the  motor  to  be  described  and  proportion- 


302 


IIOMR  MI<:CIIy\NlCS  FOI{  AJIA'I’FUHS 


alcly  .smaller  for  <li(‘  siiiiillci-  iiiolors.  Tlu'sc*  flanges  aro 
iiiouiiicMl,  (»n(‘  on  tlie  niolor  sliafi  and  llio  (OIk'i-  on  tin* 
jn-opcller  sliaft,  so  tliat  tin*  sniallin-  runs  insick*  Uic 
larnor,  Avitli  a ck-araina*  of  about  1 incli  all  l•onn(l. 

In  tlu‘  cylindrical  sni-fac(“s  of  each  arc  cut  ci.nlit  \vi!i- 
dows,  the  ed,n(‘s  of  which  are  rounded  off  as  shown  in 
Fiji'.  278.  d'liroui'h  these  windows  a ]»i(“ce  of  cotton 
h(‘ltinji',  1 inch  wide,  is  laced  as  indicated  in  tlu*  fi^ur(‘, 
its  ends  being  cemented  tog(‘ther.  Tlu>  whole  forms  an 
inexpensive  and  satisfactoiw  cou])liTig,  which-  will 
largely  prewent  any  strain  of  tin*  shaft  dne  to  the  tlex- 
nre  of  the  boat  under  loads  in  a sc-away. 

A thrust  hearing,  to  take  np  the  forward  thrust  of 
the  screw  shaft,  is  also  necessary.  A sim])le  and  satis- 
factory type  is  illustrated  in  h'igs.  279,  280  and  281. 
Upon  the  screw  shaft  are  mounted  four  steel  collars, 
each  about  three  times  the  diameter  of  the  shaft  and 
about  1 inch  thick.  These  are  ])rovided  with  set 
screws.  A cast  iron  box  contains  the  brasses  against 
which  these  collars  work.  This  box,  it  must  be  re- 
membered, receives  the  whole  forward  thrust  of  the 
scr(‘w,  and  must  not  only  be  made  strong  enough  to  re- 
sist this,  but  also  arranged  to  communicate  the  pres- 
sure to  the  frame  of  the  boat.  A good  plan  for  mount- 
ing it  is  to  place  in  the  bottom  of  the  boat  a stout  tim- 
b<‘i-,  long  (‘nough  to  b(“  sciaoved  to  several  of  the  after 
frauK'S,  and  arrange'  the  thrust  bearing  with  lugs  for 
four  or  six  lag  screws  so  that  it  may  be  securely  at- 
lached  <o  this.  In  the  size  of  boat  described  above,  at 
full  sjtee-d,  I he  forward  ]»ush  of  the  screw  will  be  about 
229  pounds,  but  in  a sea,  or  if  th(‘r<‘  is  any  obstruction 
in  I he  way,  I his  may  b(“  <‘asily  donhh'd. 

'I'lie  b(»x  frame  of  (h(‘  (hrust  block,  as  the  illustra- 


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303 


tious  very  clearly  sIioav,  is  grooved  to  receive  three 
horseshoe  shaped  brasses,  each  about  an  iuch  thick. 
These  straddle  the  shaft  between  the  collars,  Avhich  are 
adjusted  to  bear  ecpially  ou  the  brasses.  The  box  is  filled 
with  oil  to  a level  so  that  the  collars  ruu  iu  it,  con- 
stantly lubricating  the  bearing  surfaces  of  the  collars 


and  brasses.  If  one  of  the  brasses  heats,  it  may  be 
lifted  out  and  turned  around  or  replaced  with  another 
Avithout  stopping  the  boat.  A light  hinged  cover  com- 
pletes the  thrust  block.  For  the  smaller  sizes  of  motors 
indicated  three  collars  on  the  shaft  and  tAvo  brasses 
Avill  be  sufficient. 

The  shell  of  the  motor.  Figs.  282  and  283  is  a cylin- 


304 


IIOMP]  MKCIFANICS  FOR  A:\IA'rFlM?S 


(li  ical  iron  casting  oarryinfj  the  four  polar  projortions, 
A.  It  is  shown  in  the  drawini^s  with  a perfectly  ])lain 
exterior,  bnt  it  should  be  ])rovided  with  feet.  Tliese 
are  not  shown  in  the  drawinc;,  as  they  slionld  he  made 
to  fit  the  shape  of  the  hnll. 

At  each  end  of  the  heavy  field  rin,"  is  a cylindrical 
l)rojection,  C,  stiffened  with  four  columnar  ribs,  A',  to 
receive  the  cap  screws  which  fast(‘n  on  tlu'  (uid  plate. 
The  field  casfiiii?  mav  he  finished  on  the  lathe  in  two 
operations.  It  should  he  chucked  and  the  field  bored 
out  to  a diameter  of  exactly  6t\  inches.  Upon  the  ac- 
curate boring  of  the  field  and  turning  of  the  armature, 
or,  in  other  words,  upon  keeping  the  air  spaces  as  small 
as  possible,  will  depend  much  of  the  satisfactory  per- 
formance of  the  motor. 

The  end  surfaces  for  the  reception  of  the  end  plates 
are  trued  off  at  the  same  time  the  field  is  bored,  and 
fhe  seat,  8,  for  the  brush  holder  ring,  B,  is  also  turned. 
There  is  no  necessity  for  any  finish  on  the  exterior  of 
the  field  cylinder  or  any  other  machine  work  upon  it 
except  drilling  and  tapping  four  holes  in  each  end  to 
take  the  cap  screws  holding  on  the  end  plates.  After 
the  field  is  bored  all  sharp  edges  and  corners  left  on  the 
polar  projections  should  be  neatly  rounded  off  with  a 
file. 

The  two  end  plates  are  exactly  alike,  each  carrying 
a hearing  IJ  inches  in  diameter  by  3 inches  long  for 
Ihe  armature  shaft.  They  should  be  cast  of  bronze  or 
gun  iiK'tal,  and  need  not  be  more  than  F inch  thick. 
1 ti  the  one  at  the  commutator  end  four  windoAvs  should 
be  cut,  opposit(“  the  norTual  position  of  the  brushes,  so 
thal  lhes(“  may  lx;  observed  while  the  machine  is  run- 


HOME  MECHANICS  FOR  AMATEURS 


305 


Figs.  282  and  283.  Longitudinal  and  Cross  Sections  of 

Motor  Shell, 


30G 


llOMK  iMKC^IIAMCS  FOR  AMATEURS 


Tlie  briisii  holder  ring,  /^,  Figs.  28R  and  285,  is  of 
brass  or  bronze,  ineli(‘s  outside*  diain(*t(*r  and  | ineli 
tliiek.  It  earries  tin*  four  biaisli  liold(*i's,  oiu*  of  wliiebi 
is  sliown  in  seetion  in  fdg.  285  and  in  (*l(*vation  in 
Fig.  28().  Any  design  of  I'adial  brusli  liold(*r  may  be 
used,  but  tlie  simple  foian  shown  is  (*asy  to  make*  and 
very  satisfactory.  The  body  of  it  consists  of  a brass 
box,  (‘ast  in  one  piec-e  with  the  stud  going  through  tin* 
ring,  !>,  This  is  tinish(*d  out  to  allow  the  (‘op])(*r(*d 
carbon  brush,  lixlijxf  inch(*s  in  size*,  to  slide  (*asily 
through  it.  A forked  ])i(*c(*  straddling  the*  n])])(*r  cor- 
ner of  this  box  cariaes  a tinger  Ayhich  is  pr(*ss(*d  ui)on 
the  butt  of  the  brush  by  the  steel  spring  and  thumb 
screw  arrangement  shown. 

The  dimensions  of  the  shaft  are  clearly  indicated  in 
tlie  drawing.  The  commutator  is  by  far  best  bought, 
though  the  dra^ying  furnishes  a sufficient  indication  of 
a simple  form  to  enable  an  amateur  to  make  it  him- 
self if  he  so  desire.  It  has  48  segments  and  should  be 
4 inches  in  diameter,  2 inches  face,  and  bored  for  a 
inch  shaft. 

The  core  of  the  armature  is  6 inches  diameter  and  8 
inches  long.  The  end  plates  of  steel,  inch  thick,  hold 
tog(*ther  the  mass  of  soft  iron  disks  of  which  it  is  com- 
})os(*d.  These  should  be  a little  larger  than  6 inches 
diani(*ter  in  the  rough,  as  the  core  must  finish  exactly 
to  this  figure.  If  it  comes  out  a little  small,  the  field 
boi'(*,  which  should  Acait  upbn  the  construction  of  the 
ai'inatun*,  must  lx*  made  as  nearly  as  possible  inch 
larg(*r. 

It  is  us(*l(*ss  to  japan  or  insulate  the  disks.  Put 
1h(*ni  log(*lh(*r  as  lh(*y  ai‘(‘,  lighl(‘n  u])  lln*  nut,  N,  hb’g. 
2S5,  on  I ho  sliafl  and  jiin  il  in  place.  Th(*ii  true  oft*  the 


HOME  MECHANICS  FOR  AMATEURS  307 


surface  in  tlie  lathe  by  very  light  cuts  with  a sharp  tool 
at  rather  high  speed,  using  au  abundance  of  soapy 
water  on  the  tool.  A mirror-like  surface  may  be  at- 
tained in  this  way. 

While  the  armature  is  in  the  lathe  it  should  be  scored 
for  the  binding  wires  which  will  hold  the  coils  in  place. 
The  grooves  for  these  should  be  turned,  each  about  ^ 
inch  wide  by  a scant  tV  deep,  one  near  each  end  and 
one  in  the  middle. 


Fig.  285.  Armature  Core,  Shaft,  and  Commutator. 


The  next  operation  is  milling  out  the  slots  for  the 
winding.  There  are  48  of  these,  each  ^ inch  wide  and 
inch  deep,  equidistantlj"  spaced  around  the  core.  In 
milling  out  armature  slots,  the  tool  should  turn  at  a 
fairl}"  high  speed,  the  feed  be  very  slow  and  the  cut 
light,  and  an  abundance  of  oil  should  be  used.  If  no 
milling  machine  is  at  hand,  the  slots  may  be  planed, 
great  precaution  being  taken  to  keep  the  cut  very  light 
indeed. 

The  best  Avay  to  line  up  the  frame  of  the  motor  and 
to  be  sure  that  the  armature  is  properly  centered  in  the 


308  HOME  MECIIAXICS  FOR  AMATEUIiS 


fit'ld  bore,  is  to  wrap  tbe  arinatun*  core  witli  oik*  or  two 
layers  of  thin  ])a]K*r,  until  it  tits  neatly  in  the 
bore,  put  on  the  heads  at  (he  ends  of  the  inaehiiK*,  and 
east  Hahhitt  metal  in  (Ik*  hnsliinus.  If  tin*  (“iid  ])lates 
are  mark(“d  so  that  they  ean  h(>  ])nt  hack  in  (Ik*  saim* 
Avay,  the  armature  will  h(*  found  jo  he  eorreetly  cen- 
tered. Unless  this  is  dom*  the  electrical  balance  of  tin* 
motor  will  he  disturbed,  and  the  brushes  will  probably 
spark  and  f>ive  trouble. 

The  windin'*'  to  he  described  is  of  the  sort  known  as 
a four-pole  lap  windinf*',  and  is  one  of  the  simplest  and 
easiest  to  make  of  the  various  forms  of  interlocked 
windings.  Each  of  the  forty-eight  coils  used  is  shaped 
in  the  forming  apparatus  shown  in  Figs.  287,  288  and 
289.  This  is  in  two  parts,  a frame  for  winding  the 
coils  and  a former  for  bending  them.  The  frame  is 
simply  a piece  of  hoard  with  two  i inch  round  metal 
pins  driven  in  it,  these  being  lOf  inches  apart,  out  to 
out.  Around  these,  as  clearly  shown  in  Figs.  288  and 
289,  are  wound  six  turns  of  No.  14  B.  & S.  gauge  double 
cotton-covered  wire,  the  starting  end  of  the  coil  being 
marked  by  twisting  a loop  in  it,  as  shown  in  Fig.  289. 
The  ends  of  the  wire  should  he  left  longer  than  the  illus- 
tration shows  them,  say  about  6 inches.  When  this 
coil  is  completed,  it  should  he  tied  in  at  least  four 
places  with  small  thread  to  keep  it  in  position  when  it 
is  removed  from  the  two  pins,  and  it  should  he  well 
shellacked  with  rather  thin  varnish.  It  is  extremely 
advisable  to  make  up  at  least  five  or  six  of  the  hoards 
shown  in  Figs.  282  and  283,  as  this  enables  the  winder 
to  allow  the  coil  to  dry  to  the  proper  consistency  of 
“tackiness”  before*  it  is  r(*moved  from  the  frame,  and 
also  periuils  the*  coils  to  bee  made  much  more  rapidly 


HOME  MECHANICS  FOR  AMATEURS  309 


than  if  it  were  necessary  to  wait  each  time  for  the  wire 
to  dry  ont  before  winding  the  next. 

The  correct  state  of  dryness  of  the  shellac  for  the 
next  operation  must  be  learned  by  experience.  It  is 
when  it  is  at  its  stickiest.  When  this  condition  is 
reached,  the  coil  is  removed  from  the  frame  and  placed 
in  the  apparatus  shown  in  Fig.  287  to  he  formed.  This 
machine  is  made  of  a wooden  base  hoard,  on  Avhich  is 
screwed  a hard  wood  shaping  piece  of  the  dimensions 
shown  and  about  | inch  thick.  Two  hinged  pieces,  as 
shown,  are  provided,  so  that  when  the  straight  coil  as 


Figs.  287,  288,  289. 

Board  for  Forming  and  Bending  Coils. 


Fig.  286. 
Brush  Holder. 


it  comes  from  the  winding  board  is  laid  centrally  upon 
the  forming  piece,  and  both  the  hinged  pieces  bent 
over,  it  will  be  bent  into  a form  somewhat  like  a wide 
inverted  U.  The  illustration  shows  a coil  of  only  one 
layer  being  bent.  There  will  be,  of  course,  six  wires  in 
each  side  of  the  coil,  or  twelve  in  all  to  be  bent. 

When  this  bending  operation  is  completed,  and  be- 
fore the  shellac  is  finallv  hard,  the  bent  coil  must  be 
pulled  apart  so  that  six  of  its  wires,  those  tied  to- 
gether on  one  side,  may  be  laid  in  a slot  of  the  armature, 
and  the  remaining  six  wires,  forming  the  other  long 


310 


IIOMF.  IMFCIIAXK^S  KOI?  A:\IA30^ri?S 


straif»lit  side  of  ilu*  Ixail  coil,  laid  in  tin*  slot  !)()  <I(*i;r(M*s 
away.  In  otlua'  woi'ds,  tlie  (‘oil,  wlnni  it  is  jnit  oii  tli(‘ 
arinatiirc',  niiist  rc^acOi  fi'oni  slot  1 to  slot  0),  assnininij;- 
that  tliey  are  ('onscxait iv(‘ly  nnndxn'ed.  Tin*  ai)])(*ar- 
anee  of  tli(‘  tinisluMl  (-oil,  ix^ady  to  jnit  on  tli(‘  armature*, 
is  indicated  by  21)0. 

A i>lanee  at  21)1,  wldi'li  shows  tin*  (*nd  of  tin*  arm- 
ature partially  wound,  will  make  this  (‘l(*ar(*r.  Tin* 


Fig.  290.  Completed  Coils,  Ready  to  be  Mounted  on  Armature. 


Pig.  291.  End  of  Core,  Showing  Arrangement  of  Coils. 

eoils,  if  jiropei'ly  bent,  will  lie  elose  together  on  the 
h(*ads  of  tin*  armature  and  jirodiu'e  the  very  neat  and 
sim])l('  int(*rloek(*d  end  arrangement  shown  in  the  il- 
Inst  rat  ion. 

\\  ln*n  ail  tin*  foi*ty-(*ight  (‘oils  are  in  ])la(‘e,  the  arnia- 
tnF‘(*  is  i‘(*ady  foi‘  banding.  In  the  shallow  S(‘()r(*‘S  on 
I In*  snrfa(‘(*  ar(‘  laid  thin  strijis  of  mi(‘a,  the  armature 
b(*ing  in  (‘(*nt(*rs  on  tin*  latln*  for  this  operation,  or 


HOME  MECHANICS  FOR  AMATEURS 


311 


otherwise  iiioniit<‘(l  so  tliat  it  can  he  turned  around. 
It  is  better  to  catch  tlie  niica  strips  under  a cord 
wrapijed  around  the  core  a few  turns  than  to  attempt 
to  stick  them  on  witli  shellac.  On  the  mica  is  wound 
the  band,  consisting  of  about  No.  24  gauge  German  sil- 
ver or  hard  brass  wire  wound  under  the  strongest  ten- 
sion it  will  stand.  The  band  should  net  be  more  than 
t\  inch  w ide,  tlie  number  of  turns  depending,  of  course, 
on  the  gauge  of  the  band  wire.  Above  all,  care  must 
be  taken  not  to  have  this  so  large  or  the  mica  so  thick 
that  the  bands  project  above  the  armature  surface,  as 
the  clearance  space  is  very  small  and  the  bands  are 
liable  to  injury  in  putting  the  armature  in  place  or  re- 
moving it. 

When  the  band  wire  is  wound  on,  it  is  soldered  with 
five  or  six  little  dabs  of  solder,  not  continuously,  and 
the  ends  cut  off.  Three  bands  will  be  recpiired,  one 
within  about  4 inch  of  each  end  of  the  armature  core 
and  the  other  at  the  middle. 

The  commutator  is  held  from  turning  on  the  shaft 
by  a feather  (not  shown  in  the  illustrations),  and  is 
sufficiently  held  endwise  by  the  ninety-six  wires  sol- 
dered into  it.  To  connect  these,  take  the  beginning 
end  of  any  coil,  marked  by  the  little  loop  twisted  in  it, 
and  solder  it  and  the  ending  end  of  the  next  coil  in 
regular  order,  either  Avay,  into  the  slot  in  the  tail  of 
the  commutator  bar  nearest  in  line.  Proceed  around 
the  armature  in  this  regular  order,  being  very  careful 
to  bring  the  ends  out  neatly  and  not  to  pull  the  head 
of  the  winding  to  pieces  in  so  doing.  No  acid  should 
be  used  as  a flux  in  soldering  commutator  connections. 
The  only  safe  thing  is  rosin.  A narrow  edged  solder- 
ing iron  that  wall  go  into  the  slot  in  the  commutator 


312 


HOME  MECHANICS  FOH  .UWTKUPyH 


bar  will  bo  foiiiid  vory  oonvoiiicait  for  lliis  work.  It  is 
woll  to  wind  some  tajx^  around  tlu^  ininn*  Ind)  of  tln^ 
(‘oniinntator  before  l)ei» inning  the  sol<l(n'in^.  \\di(*n  it 
is  finished^  a lay(‘r  of  stout  (‘ord  sbonld  1)(‘  wound  on 
over  tlie  bnneb  of  ends  i»()in^  to  tlie  (‘ominntator  to  k(x*j) 
tliese  from  spreadin<j^  from  (*entrifn^al  acdion  wlien  tlie 
armature  is  rnnnin<»'.  Tlu^se  (‘oninintator  eoniKM'tions, 
ready  for  tlie  (‘ord  wra])j)inj>:,  are  shown  in  Fii».  292. 

The  armature  is  (completed  by  ladnij^  returmxl  to  the 
lathOj  where  a light  out  is  taken  over  the  commntator 


Fig.  292.  End  of  Completed  Armature,  Showing 
Commutator  Connections. 


to  true  it  and  cut  off  any  straggling  wire  ends.  The 
armature  should  be  baked  over  night  in  an  oven  to 
thoroughly  dry  it  out  before  it  is  attempted  to  use  it  in 
the  motor. 

On  each  of  the  four  poles  of  the  field  is  fastened,  with 
small  brass  angle  pieces,  as  (dearly  shown  in  Figs.  282 
and  28M,  a coii  (‘onsisting  of  twenty-five  turns  of  No. 
b H.&  S. gauge*  wire*,  arranged  in  five  layers  of  five  turns 
(*a(di.  The*se*  e*oils  are  wound  on  a Avooden  former  and 
tape*d.  The*ir  inne*r  ends  should  be  marked  in  some 
conv(*ni(*nt  way,  and  the*y  slioulel  be  connected  to- 


HOME  MECHANICS  FOR  AMATEURS 


313 


getlier  so  tliat  they  magnetize  the  fields  alternately 
north  and  south  when  a current  is  sent  through  the 
four  in  series.  Calling  them  Aj  B,  C,  and  D,  this  is 
done  thus:  Bring  out  the  outer  end  of  A through  a 
hard  rubber  bushing  in  the  commutator  end  plate  (the 
end  plate  at  the  commutator  end  of  the  motor),  then 
connect  the  inner  end  of  A to  the  inner  end  of  B,  the 
outer  end  of  B to  the  outer  end  of  C,  the  inner  end  of 
C to  the  inner  end  of  D,  and  bring  out  the  outer  end  of 
D through  another  bushing. 

Two  other  bushings  are  provided  for  bringing  out 
the  ends  of  the  wires  to  the  brushes.  The  four  brushes 
are  connected  in  two  pairs,  opposite  brushes  being  con- 
nected together  and  to  one  of  the  leading-out  wires. 
These  connections  should  be  made  with  No.  8 wire  and 
the  leading-out  wires  should  be  No.  6 flexible  rubber 
insulated  cable. 

Should  it  be  desired  to  construct  motors  of  this  type, 
but  of  less  power,  the  same  general  instructions  should 
be  followed,  the  diameter  of  the  armature  and  casing 
being  the  same,  but  their  lengths  different.  Below  are 
given  dimensions  and  speeds  for  motors  of  two  and 
three  horse  power;  where  a dimension  is  not  given,  it 
is  the  same  as  that  described  above  for  the  motor  of 
four  horse  power.  The  slots  for  the  three  horse  power 
armature  should  be  J inch  wide  and  | inch  deep;  for 
the  two  horse  power  armature,  ^ inch  wide  and  tV  inch 
deep. 

The  motor  now  being  complete,  the  next  part  of  the 
boat’s  equipment  is  the  controller.  The  design  shown 
is  exceedingly  simple  and  easy  to  make.  Referring  to 
Figs.  293,  294,  and  295,  which  show  it  in  section, 
and  Fig.  296,  which  is  a diagram  of  its  connections,  its 


314 


WOUK  .MI^:CIIAXICS  KOI?  AMATKl  h^S 


(‘()iistni(4 ion  and  opca'a! ion  will  1)(‘  laanlily  niKha'slood. 
It  lias  Ikmmi  llioniL;lil  ))(*st  nol  to  coniplioatc*  its  (‘on- 
strnction  liy  att(an])tini>  to  coinhiiK*  tin*  ali(*a(l  and 
astorn  (‘ontrolliniL;  niovcainaits  with  thos(*  foi'  sp(*(*ds,  so 
two  liandl(^s  ai'(^  ])i()vid(M],  om^  .nivint;  half  th(‘  full 
s])oods  and  th(‘  otlna-  for  i'(*v(‘rsini»'  tlu^  boat’s  dir(‘(*tion. 
Th(‘se  ar(‘,  how(‘V(‘r,  foi‘  (*onvcaii(ai(‘(*,  nionnt(*d  at  tln^ 
two  ends  of  th(‘  eylindi4(‘al  (-asc^  of  tlu^  (*onti‘oll(a‘.  The 
best  material  for  this  is  wood.  It  should  lx*  about  10 
or  12  iiudies  in  diameter  outside,  and  about  1 inch  thick 


Fig.  293. 

Cross  Section  of  Speed  End 
of  Controller. 


Fig.  294. 

Longitudinal  Cross  Section 
of  Controller. 


by  about  9 or  10  inches  long,  and  is  conveniently  built 
11])  in  the  way  descallxxl  above  for  the  pattern  for  the 
ti(4d  (‘asting.  It  should  be  of  wood  on  account  of  the 
insulating  jirojauTies  of  that  material. 

In  this  woodim  ('ylinder  are  mounted  two  wooden 
disks,  about  an  imdi  l(*ss  in  diameter  than  the  internal 
iiK^asurcmient  of  th(‘  (‘ontaining  (‘vlinder.  These  two 
disks  are  turiuMl  by  th(‘  two  handles — the  speed  and 
direction  handl(‘S — and  c'arry  on  their  surfaces  copper 


sectors  which  are  set  into  tlie  Avood  so  as  to  lea\’e  a 
siuootli  surface  for  running  under  the  connecting 
points.  These  are  aacII  shoAA’u  in  cross  section  in  Fig. 
293,  AA’hich  is  a partial  cross  section  of  the  speed  con- 
trolling end  of  the  apparatus.  They  consist  of  brass 
tubes  about  1 inch  in  diameter,  4 inches  long,  and  tV 
inch  thick,  containing  a spring  and  a contact  piece 
(brass  or  copper),  fitting  the  tube  neatlj^  and  pressed 
by  the  spring  into  contact  AA’ith  the  surface  of  the  disk. 
Nine  of  them  AA’ill  be  required. 


Pig.  295.  Cross  Section  of  Reversing  End  of  Controller. 

At  the  speed  control  end  of  the  apparatus  the  turning 
disk  carries  tAA"0  short  sectors  on  opposite  sides,  these 
being  connected  together  as  shoAvn,  and  tAA’O  longer  sec- 
tors extending  through  about  80  degrees  of  the  cir- 
cumference. These  are  also  folded  over  on  to  the  hack 
of  the  disk,  as  shoAvn  by  dotted  lines  in  Fig.  286,  so  that 
tAvo  of  the  spring  contacts  may  also  bear  upon  this  sur- 
face. The  easiest  Avay  to  make  these  sectors  is  to  cut 
the  parts  out  of  tV  inch  sheet  copper,  and  mount  them 


316  HOME  MECTTANTCS  FOE  AMATEUKS 


on  tlio  wood  with  small  (*oiint(‘rsunk  wood  screws. 
The  (‘irenmfer(‘ntial  and  fiat  ])arts  of  the  scM'tors  last 
deseribcnl  may  well  he  soldered  to.^ethei'  aftca*  tluw  ar(^ 
in  place  on  the  disk.  In  all  (-ases  the  S(H*toi‘  should  Ix^ 
let  into  the  wood  so  that  there  will  Ix^  no  shoahhu*  to 
(‘atch  af^ainst  the  S])ring’  contact  when  th(‘  disk  is 
turned. 

At  the  s])eed  (‘ontrol  end  of  the  apparatus  four  of  th(^ 
s])rino*  (‘onta('t  tubes  are  mountcxl,  hearinii^  u])on  th(‘ 
edf»e  of  the  disk  as  shown;  tlu^  four  Ixu'ujlj;  in  opposite^ 
pairs  ()0  dei>rees  apart.  Tn  the  int(U'ioi‘  of  the  cylin- 
drical (-ase  of  the  controller  are  two  ])artitions  as 
shown  in  Fig*.  294,  the  one  nearest  the  speed  control 
disk  just  described  carrying  two  of  the  spring  contacts 
bearing  on  the  flat  sectors  as  shown  by  the  dotted  lines 
in  Fig.  293.  These  bear  at  points  on  the  same  diameter 
connecting  two  of  the  edge  bearing  contacts. 

At  the  other  end  of  the  controller  is  mounted  the 
mechanism  for  reversing,  which  is  shown  in  partial 
section  in  Fig.  295.  This  consists  also  of  a disk  carry- 
ing on  its  edge  three  sectors,  two  of  them  only  long 
enough  to  be  entirely  in  contact  with  the  spring  con- 
tacts as  shown,  and  the  other  long  enough  to  bridge 
two  of  them,  about  fifty  degrees.  Three  of  the  spring 
contacts  are  mounted  bearing  on  these,  30  degrees 
a})art.  The  long  sector  is  connected  to  the  further  of 
the  two  short  on(\s,  Avhile  the  middle  sector  is  connected 
to  th(‘  ])ivot  of  th(^  disk  and  thus  to  the  bushing  in  which 
it  turns.  As  Fig.  294  shows,  this  is  made  quite  long, 
as  Ibis  (‘ontacl  has  to  (‘ariw  large  currents.  It  should 
not  )x‘  l(*ss  than  1hi‘(*(‘  incln^s  long,  the  pivot  being  a 
pi(x*(‘  of  on(‘  inch  shaft  ing. 

K(*f(u*ring  now  to  Fig.  290,  the  operations  of  the  (‘on- 


, HOME  MECHANICS  FOR  AMATEURS 


317 


troller  will  be  easily  understood.  It  shows  the  connec- 
tions for  half  speed  ahead.  The  diagram  shows  the 
two  sides  of  the  controller  separated,  for  the  sake  of 
clearness,  but  it  is,  of  course,  understood  that  they  are 
no  further  apart  than  the  two  ends  of  the  wooden  box 
in  which  they  operate.  The  fuse  shown  in  the  circuit 
between  the  pivot  of  the  reversing^  controller  and  the 
inner  spring  contact  is  mounted  in  the  middle  division 
of  the  box,  which  should  have  a door  for  access.  It 
should  be  an  ordinary  single-pole  iDorcelain  fuse  block 


Fig.  296.  Diagram  of  Controller  Connections. 

carrying  a fuse  blowing  at  about  75  amperes.  For 
the  3 horse  power  motor  it  should  blow  at  (>0  amperes, 
and  at  40  amperes  for  the  2 horse  power  motor. 

The  controller  box  is  easiest  made  of  some  soft  wood, 
such  as  white  pine.  It  should  be  liberally  varnished 
outside  and  lined  inside  Avith  asbestos  paper,  glued  or 
tacked  in  place.  The  two  disks  should  be  of  hard 
Avood.  On  the  exterior  of  the  box  should  be  marked 
the  positions  for  the  various  speeds  and  directions,  or, 
if  the  constructor  feels  so  disposed,  he  can  mount  a 
position  cam  and  roller  on  each  pivot. 


318 


IlOMl^:  MKCMIAXIC'S  FOR  AMAIO^FRS 


Tlie  controller  may  Re  ])la(‘e(l  aiiywlHM'e  in  tli(‘  boat, 
bnt  i)referably  \vli(a-(^  it  (an  inanipnlatcMl  by  tln^ 
j)ilot^s  left  hand  whiles  In^  stcxn's  witli  Ins  I'i^lit.  All  tin* 
wirin<»’  between  the  batteri(*s,  motor,  and  controlh*i* 
shonld  be  run  with  i»()od  ((nality  rnl)b(*r  (‘ov(*i'(*d  win*, 
No.  4 gani»e,  and  pr(*f(*rably  in  iron  armor(*d  (*ondnit,  so 
that  it  may  not  be  disturbed  by  ])ass(*n<>(*i‘s  walking 
on  it. 

The  24  (‘ells  of  battery  may  In*  conyeni(*ntly  (*har<»(*d 
from  a 110  volt  source  of  sn])ply  by  tin*  ns(*  of  a r(*sist- 
ance.  This  slnndd  be  of  about  3 ohms  and  is  conven- 
iently made  of  iron  win^,  about  No.  14  i>a)ii»e.  About 
350  feet  of  it  will  be  re(piir(*(l,  and  this  may  In*  (‘onven- 
iently  coiled  u])  in  loose  coils  and  hnnj[>  in  a frame. 
It  shonld  not  be  confined,  bnt  allowed  to  have  free  cir- 
culation of  air,  as  it  Avill  warm  up  (‘onsi(l(*rably.  The 
charsiiis*  current  shonld  be  about  20  amperes.  Fhill 
charge  is  determined  either  by  the  voltmeter,  which 
will  then  read  50.5  volts,  or  by  the  ^Omiling’’  of  the 
(‘(*lls.  It  is  a waste  of  current  to  attempt  to  further 
(‘harge  a cell  after  it  begins  to  ^dioil.’’ 

If  the  amateur  so  desires  he  may  make  his  own  cells, 
bnt  he  is  likely  to  have  more  satisfaction  with  those 
h(*  buys.  For  the  larger  size  of  motor  described  these 
c(*Ils  shonld  be  made  with  plates  8 inches  square,  15 
l(*a(l  plates  and  10  zinc  plates  to  each  cell. 


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319 


THE  EDISON  DYNAMO  OK  MOTOK 

It  is  one  thing  to  make  a dynamo  or  motor  from 
explicit  instructions  and  quite  another  tiling  to  design 
a machine  adapted  to  generate  or  be  operated  by  a 
particular  current.  The  former  is  purely  mechanical 


Fig.  297.  Small  Edison  Dynamo  or  Motor. 


and  within  the  range  of  most  machinists  and  amateurs, 
while  the  latter  is  entirely  tvithin  the  province  of  the 
electrical  engineer  or  electrician.  When  the  tvork  of 
machine  building  proceeds  simultaneously  with  the 


320 


HOME  MECHANTCS  FOR  A]\rATEURS 


study  of  fundamontal  i)i'iTi(  ij)l(“S,  roal  progress  is  made. 
For  tile  benefit  of  tliose  wlio  proeei'd  in  tliis  way,  and 
in  answer  to  many  imjnirers,  w(‘  "ive  a detailed  deserip- 
tion  of  an  Edison  0.25  kilowatt  maeliine,  dc'si^ned  for 
use  as  a dynamo  for  siipplyinij  a current  for  five  Edison 
standard  lamps,  or  for  use  on  the  PFlison  circuit  as  a 
quarter  horse  power  motor. 

Before  heginninjj;  the  desci  iption  of  the  machine  it  is 
hut  fair  to  say  that  it  is  thoroughly  well  made  in  every 
particnilar.  The  insulation  in  every  part  is  very  per- 
fect, and  the  whole  is  so  well  made  that  any  single 
machine  built  by  a mechanic  or  amateur  could  hut 
suffer  by  comparison  with  it;  and  furthermore,  we 
doubt  if  any  maker  of  a single  machine  could  even 
purchase  the  materials  required  for  the  price  asked  for 
the  machine  by  the  regular  manufacturers.  Therefore, 
if  the  machine  is  wanted,  we  advise  a purchase.  If 
experience  is  wanted,  the  making  of  the  machine  comes 
first  in  order,  Avith  a probable  purchase  to  follow. 

The  base,  which  is  of  brass,  is  made  hollow,  as 
shown.  It  is  14  in.  long,  If  in.  wide.  If  in.  deep  at 
the  ends,  with  two  1^  in.  eleA’ations  at  the  middle  for 
receiving  the  cast  iron  pole  pieces  of  the  field  magnet, 
Avhich  are  each  secured  to  the  base  by  two  small  tap 
holts  extending  upwardly  through  the  base  and  into 
the  pole  pieces. 

The  upper  surfaces  of  the  pole  pieces  are  truly  faced 
for  receiving  the  cylindrical  field  magnet  cores,  which 
are  made  of  Swedish  iron,  2if  in.  in  diameter  and  44 
in.  long.  These  magnet  cores  are  each  held  in  position 
by  a threaded  stud  screwed  into  the  pole  piece  and 
entering  magnet  core.  Each  core  is  provided  with  a 
vulcanized  lilxT  collar  at  each  end,  Avliich  is  in.  thick 


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321 


and  f in.  wide.  Upon  each  core,  and  between  the 
fiber  collars,  is  wound  5^  lb.  of  No.  24  silk-covered 
copper  wire,  with  a wrapping  of  thin  varnished  paper 
between  the  layers.  The  cores,  before  winding,  are 
thoroughly  insulated  with  the  same  material.  The 


Fig.  298.  Side  Sectional  Elevation  of  Dynamo. 

fiber  collars  are  each  held  in  place  by  three  conical- 
headed screws  entering  the  end  of  the  core,  with  their 
heads  projecting  beyond  the  body  of  the  core.  To  the 
inner  and  outer  ends  of  the  winding  of  each  arm  of  the 
magnet  are  attached  pieces  of  larger  wire  to  avoid 


322 


.MKClJAX’K’S  KOI?  AMA'IMaUH 


breakajic,  and  the  inner  ends  ai‘<‘  l(>d  nut  tlironp;!! 
j>r()()ves  in  tiie  fiber  collars.  The  vok(‘,  of  Swedish 
iron,  is  2|  in.  wide,  2^  in.  thick  and  TA  in.  long.  It 
is  held  in  position  on  tin*  cores  by  two  A bronze 
stiids,  each  tlir(*ad(‘d  at  the  iipper  and  lower  ends,  and 
furnished  with  a collar  which  tits  into  the  counter- 


Fig.  299.  Side  View  of  Field  Magnet,  Partly  in  Section. 

bored  part  of  the  hole  in  the  yoke.  The  studs  are 
s<piared  sit  the  upper  end  to  receive  a wrench,  and  a 
nut  is  placed  on  each  stud  above  the  yoke  for  clamp- 
ing it  securely  after  adjustment.  The  machine  is  regu- 
lated or  adapted  to  any  work  retpiiring  less  than  its 
full  power  by  raising  the  yoke  more  or  less.  The  yoke 


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323 


is  provided  with  an  eye,  by  means  of  which  the  ma- 
chine may  be  lifted. 

Front  and  rear  boards  of  mahogany  are  arranged  on 
opposite  sides  of  the  yoke,  and  held  in  place  by  brass 
plates  at  the  ends. 

The  outside  ends  of  the  field  magnet  coils  are  con- 
nected with  binding  posts  on  the  rear  board. 

A variable  resistance  of  ten  or  fifteen  ohms  is  in- 
serted between  these  posts  when  the  machine  is  used 
as  a dynamo.  In  the  front  board,  at  the  right  hand 
side,  is  secured  a bronze  casting  known  as  the  right 
hand  motor  head  field  magnet  terminal.  This  is 


Fig.  300.  Switch  on  the  Edison  Dynamo  or  Motor. 


adapted  to  receive  the  line  wire,  also  one  of  the  leads, 
the  upper  end  of  which  is  screwed  to  the  casting.  The  * 
lower  end  of  the  lead  is  secured  to  a lead  terminal 
attached  to  a block  of  wood  secured  to  the  right  hand 
pole  piece.  At  the  right  hand  side  of  the  machine  a 
similar  arrangement  of  the  lead  is  found,  but  the  up- 
per lead  terminal  is  made  in  two  separate  parts,  one 
attached  to  the  lead,  the  other  being  connected  with 
the  line;  both  being  furnished  with  copper  switch 
tongues.  The  switch  arm  turns  on  a stud  projecting 
from  the  front  board  and  carries  a loose  triangular 
switch  plate  of  copper,  having  a knife  edge  which 


324  TrOMI<]  I\IRCITANFCS  FOl?  A:\IATKUKS 


readily  oidoi-s  lK>t\vo(ai  tli(‘  swilcli  loiioiu-s.  Tlie  switch 
has  a T-haiidl(''  <»f  lull'd  ruhhia',  hy  mi'ans  of  which  it 
is  turned.  A stoi)  ])in  ])i'(>j<“ctinf^  fi-oiu  llic  front  hoard 
limits  till'  rearward  moymiumt  of  tli(‘  switeli  arm. 

The  inside  end  of  the  I'i^ht  mai^md  coil  is  eonneeted 
with  the  right  hand  lead,  and  lln^  iiisidi^  mid  of  the  left 


Fig.  301.  Diagram  of  Winding  of  Edison  Armature. 

liand  magnet  coil  is  connected  with  the  lower  half  of 
till*  left  liand  lead  terminal. 

At  oi)])osit(‘  ends  of  th<‘  base  there  are  plane  surfaces 
io  wliicli  are  si'cnred  tin*  self-oiling  hearings  of  the 
armalnrc*  shaft,  hlach  l)(>aring  has  a hollow  standard 
fnrnislied  wilh  a caii,  wliich,  together  with  a cross 
jiieci*  in  lh(‘  hollow  standard,  forms  a support  for  the 


HOME  MECHANICS  FOE  AMATEUES 


325 


spherical  central  portion  of  the  bronze  sleeve  forming 
the  journal  box  proper. 

This  sleeve  is  shorter  than  the  outer  portion  of  the 
bearing,  and  is  slotted  across  the  top  to  allow  two 
brass  rings  to  ride  upon  the  armature  shaft.  These 
rings  dip  in  the  oil  in  the  hollow  standard,  and  as  they 


Fig.  302.  The  First  Two  Coils  and  Commutator  Connections. 

revolve  carry  oil  to  the  shaft  in  quantities  more  than 
sufficient  for  the  purpose  of  lubrication.  The  oil  is 
distributed  throughout  the  bearing  by  means  of  spiral 
grooves  formed  in  the  inner  surface  of  the  journal  box. 
The  surplus  oil  drops  back  into  the  hollow  standard. 
A screw  plug  in  the  lower  portion  of  the  standard 
allows  of  the  renewal  of  the  oil.  The  bearings  at 


326 


HOME  MECHANICS  ECU  AMA'l'EUES 


op2)(»site  ends  of  Hie  iiiacliine  are  alik(‘,  exci'pl  (liat  Hie 
cast  ii'on  supiioi-t  of  Hi(‘  Iiionze  joui'iial  box,  at  the 
coiiuimtator  end  of  Hie  armature,  is  turned  on  its  inner 
end  to  receive  the  hrusli  3’oke. 

Tlie  steel  armature  sliaft  is  l(i|  inches  ionj^  and 
inch  in  diameter  at  tlie  journals,  and  incli  in  diame- 
ter between  the  journals.  The  lari>ei‘  part  of  the  shaft 


Fio.  303.  Arrangement  of  the  Layers  at  End  of  Armature  Core. 

is  It]  inclii's  louo-.  Sufficient  end  chase  is  allowed  in 
the  armature  journals  to  cause  the  surfaces  to  wear 
smooHilj. 

On  (he  central  jiortion  of  the  armature  shaft  is 
jilaced  a woodmi  sl(‘ev(“,  liV  inch  in  diameter;  on 
this  are  moun((‘d  Hi(‘  thin  sh(‘(‘t  iron  disks  forming'  the 


HOME  MECHANICS  FOE  AMATEUES 


327 


They  are  arranged  in  series  of  five,  with  tissue  paper 
betW'een  the  disks,  and  between  the  series  of  five  are 
placed  several  thicknesses  of  paper.  Enough  disks  are 
clamped  together  on  the  shaft  to  make  this  portion 
of  the  core  inches  long.  The  cast  iron  disks  be- 
tween which  the  sheet  iron  disks  are  placed  are  | inch 
in  thickness  and  2^  inches  in  diameter.  One  of  them 
is  fixed  on  the  shaft,  the  other  being  held  in  place  by  a 
hexagonal  nut  screw'ed  on  the  shaft.  The  cast  iron 
disks  have  their  outer  corners  rounded,  and  in  the 


Fig.  304.  The  Ends  of  the  Armature  Core. 


edge  of  each  are  formed  thirty-two  equidistant  radial 
slits  inch  wdde.  In  these  slits  are  inserted  slips  of 
vulcanized  fiber  for  separating  the  different  pairs  of 
coils  during  the  operation  of  winding. 

It  is  impossible  to  describe  the  Edison  wunding  wuth- 
out  depending  mainly  on  the  diagrams.  Figs.  301  and 
302.  There  are  tw’o  series  of  coils ; that  is  to  say,  there 
are  tw'o  coils  in  each  division  of  the  armature  There 
are  thirty-two  bars  in  the  commutator,  w hich  are  num- 
bered consecutively  from  1 to  32. 


328 


JJOMK  MI^XMIANICS  FOH  A:\IATKT;HS 


The  arinatiir(‘  core  and  sliaft  arc^  tlK)r()iii»:lily  insu- 
lated by  means  of  i)a])(n‘  eoated  witli  an  adh(*sive  var- 
nish. Jnte  strini*'  ril)l)()n  is  wound  on  tlie  fa(‘e  of  tlie 
core  as  a fiirtluT  ])rot(‘(‘tion. 

The  wire  nsed  on  the  armature  is  No.  21  (‘0])i)er  wire, 
double  covered;  tlie  inner  eoverinii;  beinj>^  of  silh,  the 
outer  of  (‘otton. 

Leavinf»'  an  end  out  for  connection  witli  tlie  commu- 
tator (‘oil,  No.  1 is  bej»un  at  1 and  wound  in  four  lay- 
ers, with  six  convolutions  in  each  layer,  the  outer  ter- 
minal eominf>‘  out  at  T.  Tlu^se  (mds  are  niarkc^d  re- 
spectively 1 and  1'  in  such  a manner  as  to  avoid  any 
possibility  of  the  detachnumt  of  the  marks.  If  this 
caution  is  observed,  much  trouble  may  be  avoided. 
A good  Avay  to  mark  them  is  to  jilace  a tag  of  parch- 
ment, or  parchment  paper,  on  each  end  of  the  wire, 
with  the  number  marked  on. 

After  winding  coil  No.  1 the  armature  is  turned  half 
way  over  and  coil  No.  2 is  wound  and  marked  in  the 
same  way,  with  2 on  the  inner  end  of  the  coil  and  2'  on 
the  outer  end.  The  coil  is  then  reversed  and  coil  No. 
3 is  wound  and  its  ends  are  marked  in  the  same  way, 
and  so  on  until  the  first  series  of  coils  is  finished,  the 
last  coil  of  the  series  being  marked  16  and  16'. 

The  first  (-oil  of  the  outer  series  is  No.  17-17'.  This 
is  wound  on  the  top  of  coil  No.  1.  The  armature  is 
turned  over  and  No.  18  is  wound  on  the  top  of  No.  2, 
and  so  on  until  all  of  the  outer  coils  are  in  place. 

I>(d‘or(‘  winding,  the  inner  end  of  each  wire  is 
wrapper!  in  jnt(‘  string  ribbon  to  a point  within  the 
(*nd  of  th(‘  armatnT‘(‘  core,  and  it  is  further  protected 
by  a wi'apping  of  Ihin  adh(‘siv("  taj)e.  The  outer  end  of 
the  coil  is  (‘ov(*r(Ml  in  the  same  Avay. 


HOME  MECHANICS  FOR  AMATEURS 


329 


About  three  pounds  of  No.  21  wire  are  required  for 
the  armature.  The  length  of  wire  in  the  first  inner 
coil  is  26  feet  6 inches.  The  length  of  wire  in  the  last 
outer  coil  is  35  feet. 

The  commutator  cylinder*  is  formed  of  32  bronze 
bars  having  beveled  ends  and  radial  arms  for  receiv- 
ing the  wires.  These  bars  are  clamped  in  position  on 
a sleeve  having  an  under-cut  flange,  by  a countersunk 
washer  and  a nut  screwed  on  the  sleeve.  Mica  is 
inserted  between  the  commutator  bars,  between  the 
bars  and  the  sleeve,  and  between  the  ends  of  the  bars 


Fig.  305.  The  Armature  with  Parts  Broken  Away. 


and  the  flange  and  the  washer.  The  radial  arms  ex- 
tending from  the  commutator  bars  each  have  a slot  in 
the  end  for  receiving  the  terminals  of  the  coils. 

The  coil  terminals  are  arranged  in  groups  of  16,  the 
wires  of  each  group  being  parallel.  The  terminals  are 
carried  around  and  attached  to  commutator  bars 
which  are  about  90°  from  the  planes  of  the  coils  to 
which  they  belong,  thus  making  the  winding  more 
symmetrical  and  at  the  same  time  permitting  of  a bet- 
ter arrangement  of  the  brushes. 

The  coil  terminals  are  inserted  in  the  slots  of  the 
arms  of  the  commutator  bars  and  soldered  with  soft 

* For  further  points  on  Commutators,  see  Supplement  600. 


330 


IfOMK  MPX:IIAN1CS  K()I{  AMA'I'EUKS 


solder,  the  connections  beinij  made  in  accordance  Avith 
the  diaj^i'ain,  Fio-.  301. 

The  wires,  where  tlu\y  cross  at  the  hack  and  front 
end  of  the  armature',  are  separate'd  hj  sheets  of  mica. 
^yhere  the  windinij  crosse's  at  the  rear  end  of  the  arma- 
ture the  wires  are  spread  out  so  that  they  are  only 
one  layer  deep. 


Fig.  306.  The  Brush  Yoke. 


When  the  winding  of  a coil  is  finished,  the  terminal 
is  fastened  by  stout  threads  inserted  in  the  coil  before 
winding  the  last  three  convolutions,  and  tied  after  the 
coil  is  complete. 

A vulcanized  fiber  collar,  a little  larger  in  diameter 
than  the  commutator,  is  slippi'd  over  the  commutator 
bars  and  ])laced  against  the  radial  arms  of  the  bars 
as  shown.  Tin*  edgi'  of  the  collar  is  grooved  and  a 
canvas  cov(*r  is  fasti'iied  to  the  collar  by  tying  it  in 
the  groove.  It  is  (Ik'u  drawn  over  the  terminals  and 


HOME  MECHANICS  FOR  AMATEURS  331 


fastened  by  the  first  ring  of  binding  wire  on  the  arma- 
ture. At  the  opposite  end  of  the  armature  a similar 
collar  and  cover  are  provided. 

Before  covering  the  terminals  with  the  canvas  they 
are  wound  with  twine  to  give  the  end  of  the  armature 


Fig.  307.  Details  of  the  Brush  Holder,  the  Commutator  Cylinder, 

and  Brush-holding  Jig. 

a symmetrical  shape.  The  winding  is  varnished  with 
shellac  before  its  cover  is  applied,  and  the  cover  is 
varnished  after  it  is  secured  in  place. 

The  binding  rings  are  formed  of  brass  wire,  wound 
tightly  over  a layer  of  mica  interposed  between  the 
wire  and  the  binding.  The  binding  wire  is  secured  by 
clips  and  soft  soldering. 

The  brush  yoke  is  provided  with  wooden  handle  by 


:532  HOME  MKCIIAXICS  FOI?  AMA'l’EUHS 


wliich  it  may  be  moved  and  a biiidiiifj;  scrc'w  by  wliicb 
it  is  clamped  in  the  position  of  nse.  Jn  mortises  in  the 
ends  of  tlie  yoke  are  placed  insnlaiin*;;  blocks,  in  which 
are  inserted  the  brnsbdioldinij  studs.  These  stnds  are 
each  provided  with  a nut  for  clampiiif^  the  brush 
holder  cables  which  communicate  with  the  leads  at  the 
side  of  the  pole  pieces. 

On  each  brush-holdiip"  stud  is  placed  a sleeve  fas- 
tened with  a set  screw,  also  a loose  sleeve  connected 
with  the  fast  sleeve  by  a spiral  spring  concealed  with- 
in it.  The  loose  sleeve  is  furnished  with  a brush  clamp 
for  holding  the  brush,  Avhich  bears  on  the  commuta- 
tor cylinder  Avith  a yielding  pressure.  The  brushes  are 
formed  of  spring  copper  Avires  fastened  together  at 
their  outer  ends  with  soft  solder. 

A jig  goes  Avith  each  machine  for  clamping  the  brush 
and  guiding  the  file  while  reneAving  the  brush  ends. 

The  speed  of  the  motor  on  a 125  A’olt  circuit  is  2,400 
reA'olutions  per  minute.  The  speed  at  which  the  arma- 
ture is  to  be  driven  in  order  to  generate  a current  liaA'- 
ing  an  E.  M.  F.  of  125  Amlts  is  2,730  revolutions  per 
minute. 

According  to  the  ncAv  rating  the  machine  here  de- 
sci-ibed  is  a 0.5  kiloAvatt  machine,  Avhich,  A\'hen  used  as 
a generator  for  supplying  lights,  will  generate  suffi- 
cient current  to  bring  to  full  candle  power  nine  16  C. 
P.  112  A’olt  lamps,  and  Avhen  used  for  power  it  is  a | 
horse  poAver  motor  at  a rated  volt.  It  is  guaranteed  to 
give  0.47  horse  poAver  at  J of  its  rated  volts. 


HOME  MECHANICS  FOE  AMATEUES 


333 


THE  UTILIZATION  OF  110  VOLT  ELECTRIC 
CIRCUITS  FOR,  SMALL  FURNACE  WORK* 

It  occurred  to  the  writer  in  wiring  up  a couple  of 
experimental  arc  lamps  across  the  feeders  of  an  in- 
candescent lighting  system,  that  a laboratory  electric 
furnace  could  be  operated  on  a series  carbon  plan, 
Avithout  disturbing  the  protecting  fnses  of  the  circnit. 
This  idea  of  concentrating  a pair  of  arcs  within  a 
small  crucible  or  furnace,  using  only  the  amount  of 
resistance  wire  located  in  the  tops  of  the  lamps,  proved 
to  be  crude,  the  current  taken  being  excessive  upon 
introducing  a charge  for  fusion,  when  its  character 
embodied  fair  electrical  conductivity.  In  order  to 
obviate  this  difficulty,  as  well  as  to  compensate  for  the 
lowering  of  resistance  due  to  eddy  currents  between 
the  carbons,  a triple  series  arc  was  formed  requiring 
only  a short  length  of  German  silver  wire  to  steady 
its  action.  With  this  arrangement  the  most  success- 
ful results  were  attained,  and  Avith  the  furnace,  as 
finally  constructed  upon  this  plan,  many  metallnrgical 
processes  Avere  carried  on,  a 12  ampere  fuse  placed  in 
each  leg  of  the  current  supply  being  snfficient.  The 
little  furnace  illustrated  in  Fig.  308  is  capable  of  pro- 
ducing calcinm  carbide  in  twenty  minutes  from  the 
time  the  current  is  SAvitched  on,  the  fuses  remaining 
intact  thronghout  the  operation,  if  a short  length  of 
resistance  wire  is  introduced  into  the  circnit.  With 
this  arrangement  it  is  possible  to  separate  the  carbon 
electrodes  3i  inches  without  extinguishing  the  triple 
arc.  It  is  the  intention  of  the  writer  to  describe  in 
detail  the  construction  of  this  little  plant,  and  fur- 

* By  Nevil  Monroe  Hopkins. 


334  HOMJ-:  MKCllAxNlCS  TOli  AMATEURS 


Fig.  309.  Plan  View  of  Furnace,  showing  Connections. 


HOME  MECHANICS  FOK  AMATEUES 


335 


nish  carefully  prepared  directions  for  making  small 
quantities  of  calcium  carbide.  This  compound  is 
chosen  because  of  its  exceedingly  useful  and  interest- 
ing characteristics,  and  because  of  the  numerous  in- 
quiries the  writer  has  received  in  regard  to  its  forma- 
tion on  a small  scale.  Calcium  carbide  is  a highly 
refractory  body,  its  preparation  requiring  the  highest 
temperatures,  and  its  successful  production  by  means 
of  this  small  electrical  equipment  urges  experimenta- 
tion with  other  compounds  requiring  less  energy  and  a 
lower  temperature. 

Fig.  309  will  enable  us  to  understand  the  mounting 
and  connecting  of  the  carbons,  being  a plan  view  of 
the  system.  The  steps  in  putting  together  this  little 
equipment  should  consist  in  forming  and  lining  the 
furnace  proper.  The  shell  is  made  from  sheet  iron, 
cut  to  exactly  incase  one  of  the  common  sizes  of  fire 
clay  slabs.  The  exact  size  and  shape  of  this  furnace 
is,  of  course,  immaterial,  provided  the  length  is  not 
over  13  inches  from  end  to  end,  as  shown  in  Fig.  311. 
Should  the  length  exceed  13  inches,  standard  electric 
light  carbons  would  not  prove  long  enough  to  meet  at 
the  center.  As  the  fire  clay  slabs  adapted  to  our  pur- 
pose vary  somewhat  in  length,  definite  dimensions  are 
not  given,  but  those  shown  in  Fig.  310  will  be  found 
useful  as  guides,  and  are  approximately  suited  to  the 
average  sized  slab  sold  for  backing  up  fire  places  and 
stoves,  which  are  plane  on  one  side  and  fiuted  on  the 
other.  Having  procured  four  of  these  slabs,  the  sheet 
iron  (No.  18  or  20  gauge)  may  be  marked  off  carefully 
and  bent  to  form  the  shell.  The  overlapping  sides  are 
drilled  through  and  securely  riveted  together.  One  of 
the  fire  clay  pieces  is  now  placed  in  the  shell  on  either 


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.MKCIIAXICS  F()I{  AMA'I’l'J  IfS 


Fig.  311.  Convenient  Method  of  handling  Cover. 


HOME  MECHANICS  FOR  AMATEURS  337 


side  (the  fluted  surface  next  to  the  iron)  and  a large 
fire  brick  dropped  in  between  them.  These  large  fire 
bricks  come  with  a recess  in  the  top,  as  represented 
in  Fig.  308,  which  is  desirable  for  collecting  small 
fusions.  If  the  three  pieces  of  fire  clay  fit  nicely  in 
the  shell,  the  fire  brick  is  removed  temporarily,  and 
our  attention  given  to  cutting  one  of  the  slabs  in  half 
to  form  the  ends  of  the  lining. 

In  Fig.  310  a section  of  the  shell  is  shown,  where  A 
represents  one  of  the  side  slabs  in  position,  running 
from  end  to  end,  as  illustrated  by  the  horizontal  shad- 
ing. These  slabs  may  be  had  about  12J  inches  in 
length  by  aboflt  8 inches  in  width  and  2 inches  thick, 
which  serve  for  this  lining  nicely.  The  end  pieces 
must  be  cut  off  at  an  angle  to  form  the  bottom  of  the 
incline  leading  into  the  furnace.  These  are  repre- 
sented in  the  drawing  by  section,  in  oblique  lines.  The 
fire  clay  is  cut  with  a cold  chisel  and  hammer,  work- 
ing slowly  with  uniform  blows,  exercising  some  little 
patience,  until  the  pieces  have  the  proper  shape.  The 
angle  must  be  determined  by  trial  with  the  shell,  which 
is  cut  down  by  means  of  heavy  shears,  within  5 inches 
of  the  bottom,  being  about  5^  inches  in  width.  The 
metal  flap,  resultant  of  this  cutting  down,  is  sharply 
bent  over  and  cut  off,  the  edge  being  smoothed  with 
a large  flat  file.  A band  of  iron  riveted  around  the 
top,  as  illustrated,  crowns  the  opening,  and  must  be 
adjusted  as  to  height,  by  the  size  and  thickness  of 
the  fire  clay  lining  which  has  been  procured. 

To  complete  the  furnace  proper,  it  is  only  necessary 
to  put  in  place  the  angle  pieces,  and  secure  in  position 
temporarily  four  pieces  of  glass,  in  order  to  form  the 
top  of  the  inclined  entrance.  The  wooden  brace,  B, 


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is  cut  to  the  proper  lenj^th  to  press  the  vertical  j^lasses 
(shown  ill  simple  rnliiifi)  against  tli(‘  eiul  pieces  of  fire 
clay,  and  small  wooden  blocks  made  to  support  the 
o’lass  plates  on  Hie  incline',  as  illnstratc'd,  h'aviii"  a 
2-inch  space.  The  hei<ilit  of  the  vertical  ,<>lass  plates 
nuist  he  just  eipial  to  th<‘  lii'i^ht  of  the  side  slab, 
M,  and  the  inclined  pii'ces  must  come  nicely  in 
contact  Avith  them.  The  two  sjiaces  foi-im'd,  f/  and 
Z),  are  now  filled  in  with  “stoA’e  fix’’  or  other  fire  clay 
compound  made  plastic  by  the  addition  of  a little 
water.  This  componnd  may  be  had  ready  to  mix,  and 
is  applied  with  a,  trowel.  The  glass  plates  must  be 
left  in  position  oi’er  night,  in  order  that  the  material 
which  they  support  may  set.  They  are  then  with- 
drawn together  with  the  wooden  brace,  and  the  fire 
brick  dropped  into  the  bottom  to  stay.  An  additional 
quantity  of  the  stove  compound  is  made  up,  and  all 
cracks  and  crevices  plastered  in.  When  this  finally 
sets,  a strong  and  durable  furnace  is  produced.  It 
should  be  heated  up  slowl}'  for  the  first  time  uncovered, 
in  order  to  expel  all  moisture.  The  top,  which  con- 
sists of  the  fourth  piece  of  slab,  is  cut  through  by  means 
of  the  cold  chisel,  and  is  afterward  smoothed  with  a 
large  rasp. 

The  method  of  suspending  the  cover  is  illustrated  in 
Fig.  311,  the  iron  bands  coming  OA’er  the  fire  clay  walls, 
on  the  inside,  being  thus  protected  from  the  heat  of 
the  arcs.  Having  completed  this  portion  of  the  Avork, 
th('  base,  platfoians,  and  scroAV  feed  must  be  put  to- 
gether. The  base,  upon  Avhich  the  entire,  plant  rests, 
consists  of  a h<*aA'y  pine  board,  4 feet  in  length  by  8 
inclu'S  in  Avidth.  The  furnace  is  mounted  upon  three 
common  bricks  (2|  inches  in  height)  and  placed  at 


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339 


the  center  of  the  board  to  facilitate  the  design  and 
construction  of  the  inclines,  which  must  be  very  ac- 
curately pitched,  in  order  that  the  carbons  may  be  fed 
into  the  furnace  without  coining  in  contact  with  the 
openings.  Should  they  touch,  however,  a couple  of 
mica  sheets  must  be  applied  as  a precaution  against 
short  circuits.  These  inclines  are  made  from  1 inch 
pine  boards,  6 inches  in  width  and  16  inches  in  length. 
These  boards  are  mounted  upon  upright  pieces  of  wood 
of  the  same  weight  for  trial,  but  are  not  screwed  on 
until  the  screw  feed  is  put  in  place,  which  is  attached 


Fig.  312.  Sections  of  Clamp  as  applied  to  Screw  Feed. 

from  underneath.  Of  course  the  inclines  must  be  care- 
fully adjusted  to  any  specific  furnace,  but  the  height 
of  the  front  and  back  supiiorts  will  be  about  8 and  3:^ 
inches  respectively.  These  may  be  attached  at  once  by 
means  of  strong  angle  irons  as  illustrated  in  Fig.  308. 
To  form  the  screw  feed,  select  a large  sized  furniture 
maker’s  clamp,  with  wooden  screws  at  least  18  inches 
long.  Fig.  312  illustrates  such  a clamp,  the  sections 
to  be  sawn  through  to  make  the  bearings  and  screw 
collars  being  marked  in  dotted  lines.  The  sections 
marked  8 8 will  be  found  to  contain  the  screw  threads, 
and  serve  for  the  center  traveling  pieces  upon  which 


340 


IIOMK  T\rECIIANI(;S  FOI!  AMATKl'IJS 


tlie  blocks  and  electrodes  are  nionnted.  The  sections 
1,  2,  8,  and  4 s(>rv(*  for  sini])l<‘  l)(‘arin<>s,  after  Ixdnii 
carefully  drilled  thronf>li  with  a bit  and  brac(‘,  ex- 
ercisinjj  ^Tcat  care  in  borinj;,  to  secure  centrally  located 
straijjht  holes.  These  are  screwed  on  to  the  board 
from  nnderneath,  and  as  tbe  wood  from  whicb  tbe 
furniture  clam])s  are  made  is  Aery  hard,  <^imlet  holes 
must  be  proA'ided  for  tbe  reception  of  the  screAvs  to  ])re- 
A'cnt  splittinj*.  These  nimbd  holes  must  ha\e  consider- 
able depth.  TTpon  the  traAeliiifj  pieces  are  mounted 
tAVO  blocks  (>  inches  lony,  4 inches  Avide,  and  about  14 
inches  in  thickness.  Three  brass  tulx'S  are  carefully 
mounted  upon  each  of  tln^se,  of  the  ri^ht  size  to  receiA^e 
electric  lijiht  carbons  (tbe  lonf>est  kind,  copper  coated) 
AA’itli  a tijiht  tit.  These  tubes  are  secured  as  shown  in 
Fifj.  309  by  means  of  lieavy  brass  straps.  The  car- 
bons are  placet  in  position,  about  an  inch  of  the  end 
left  protruding  to  alloAV  brass  spring  clips  to  be  pushed 
underneath.  With  this  spring  adjustment,  the  car- 
bons can  be  quickly  AAuthdraAA’n  or  easily  regulated. 
The  connections,  Avhicli  should  consist  of  double  in- 
sulated Avires  (No.  10  gauge),  are  soldered  to  these 
clips  in  the  manner  indicated.  It  will  be  obserA^ed  by 
referring  again  to  Fig.  308  that  the  carbons  may  be 
sloAA’ly  AvithdraAAii  by  turning  the  scrcAAq  or  they  may 
be  pulled  out  of  the  furnace  by  the  handle  of  the  screw 
when  it  is  necessary  to  remoA^e  the  furnace  from  the 
base. 

The  fiirnace  is  noAV  ready  for  connecting  up  and  a 
trial.  Adjust  all  six  carbons  carefully,  making  sure 
tbal  ih<*y  an*  all  in  contact.  When  tin*  tri]>le  arc  once 
forms,  th(‘y  re(|uir(‘  v(‘ry  liltb*  attention,  aiid,  as  stated, 
will  conlinm*  lo  burn  wlnm  llu*  distance  betAveen  their 


HOME  MECHANICS  FOR  AMATEURS 


341 


ends  exceeds  3 inches,  with  a charge  of  coke  and  lime 
as  the  conducting  medium.  Fig.  313  shows  the  scheme 
of  proper  connections  with  a 110-volt  electric  lighting 
system.  The  main  conductors,  or  feeders,  are  repre- 
sented at  the  bottom  by  heavy  horizontal  lines  and  are 
joined  as  indicated  direct  to  a porcelain  fuse  block,  F. 
This  connection  should  be  made  as  near  the  meter  as 
possible,  in  order  to  avoid  annoyance  from  intermedi- 
ate fuses.  In  addition  to  this,  the  capacity  of  the  meter 


Pig.  313.  Diagram  of  Connections,  with  Ammeter  and  Voltmeter 
arranged  for  studying  the  Behavior  of  Compounds 
within  the  Arc. 


should  be  ascertained,  which  should  allow  of  a 25  am- 
pere load.  In  other  words,  a 45-light  meter  will  be 
large  enough,  a standard  16  candle  power  lamp  taking 
about  0.6  ampere.  Place  a 12-ampere  fuse  in  each  side 
of  the  fuse  block,  as  shown,  and  join  the  same  to  a 
small  knife  switch,  H.  Should  the  reader  possess  an 
ammeter  (of  fully  50  amperes  capacity),  it  should  be 
included  in  the  circuit,  and  a voltmeter  should  be 


HOME  ]VII^:(UIAXICS  FOR  A^rATP^URS 


3:t2 


joined  across  tlie  connections  of  tlie  ar(‘S  if  i)ossil)l(\ 
Tlie  resistan(‘(^,  l\,  ('onsists  of  20  f(M‘t  of  douRled  (Jer- 
man  silver  wire,  No.  22  ii»an<>e,  Brown  & Sliar])e.* 

To  make  tliis  resistaiK'e  in  convenicmt  sliape,  the 
wire  should  be  wound  about  a larm^  fire  clav  slab, 
which  serves  for  siiflicaent  insulation  and  resists  the 
effect  of  the  heatinj>*  up.  This  slab  witli  its  wire  must 
not  be  phu'ed  near  woodwork.  Tln^  furmu'C^  should  be 
run  for  fifteen  or  twenty  minutes,  for  the  first  time 
without  its  cover  and  Avithout  a charii^e,  movin^e;  the 
carbons  back  and  forth  and  testing’  their  (‘enterinc^,  etc. 
Should  the  arc  i>()  out,  the  fe(Ml  is  screwed  down  until 
contact  is  again  made  and  the  incline  rai)ped  Avith  a 
mallet  in  order  to  cause  the  ])oints  of  the  carl)ons  to 
Aubrate  or  rub  together.  In  doing  this  Avork  Avitli  the 
cover  off,  use  strongly  smoked  glasses  to  protect  the 
eyes  from  unnecessary  strain.  Having  mastered  the 
handling  of  the  equipment  Ave  are  noAV  ready  for 
experimentation,  and  Avill  proceed  direct  aa  ith  the  prep- 
aration of  calcium  carbide.  To  produce  a laboratory 
quantity  of  this  compound,  folloAV  closely  the  direc- 
tions given.  Weigh  out  18  ounces  of  good  unslaked 
lime  (calcium  oxide,  CaO),  and  reduce  to  a granulated 
form  in  a large  iron  or  porcelain  mortar.  Place  this 
portion  of  the  charge  on  a large  sheet  of  manila  paper 
and  })repare  for  the  grinding  of  the  coke.  Do  not  at- 
temj)t  to  us(^  (‘harcoal,  as  it  is  too  light  and  floury, 
oxidizing  away  in  the  air  Avithout  combining  Avith  the 
]im(\ 

S(^l(*ct  (‘itlnu*  good  (*oke  or  procure  a lot  of  broken 
electric*  light  carbons,  and  Aveigh  out  1(5  ounces  of  the 

* "I'his  wiro  recniires  rmich  care  in  handling,  and,  if  allowed  to 
tangle  or  kink,  l)reaks  very  easily.  It  is  very  brittle. 


HOME  MECHANICS  FOR  AMATEURS  343 


fragments.  These  must  now  be  pounded  to  small 
pieces  and  afterward  granulated  in  the  iron  mortar  to 
about  the  same  size  as  the  pieces  of  lime.  The  coke 
and  lime  should  now  be  thoroughly  mixed  together  on 
the  large  sheet  of  paper  preparatory  to  grinding  in  an 
iron  coffee  mill.  These  mills  come  all  of  iron,  designed 
to  screw  up  against  the  wall,  and  are  equipped  with  a 
regulating  device  for  grinding  coarse  or  fine.  The 
money  put  in  a mill  of  substantial  character  will  be 
well  invested,  as  it  will  prove  of  great  value  in  a 
laboratory  or  experimental  shop  for  reducing  many 
substances  to  powder.  The  granulated  lime  and  coke 
are  poured  into  the  mill  and  ground  to  the  finest  meal, 
passing  the  mixture  through  several  times  to  insure  an 
intimate  mixing  as  well  as  a fine  powder.  Should  a 
mill  not  be  at  hand,  the  charge  may  be  reduced  to  the 
proper  fineness,  although  requiring  much  more  labor, 
by  means  of  the  large  iron  mortar.  The  pestle  of  the 
mortar  is  ground  to  the  right  and  the  mortar  rotated 
to  the  left  with  the  palm  of  the  left  hand.  There  is  a 
little  knack  in  doing  this,  and  Avith  a little  practice, 
but  Avith  considerable  work,  the  lime  and  coke  may  be 
suitably  prepared  for  fusion. 

The  poAvdered  charge  must  be  put  away  in  airtight 
receptacles,  if  it  is  not  intended  for  immediate  use,  as 
the  lime  in  the  finely  poAvdered  state  quickly  slakes  if 
left  in  contact  Avith  the  air.  Sliould  we  use  the  mix- 
ture Avithout  thoroughly  grinding,  Avhich  is  a very 
dark  slate  color,  it  Avill  be  found  a very  light  gray 
upon  shutting  doAA’n  the  furnace  after  a run,  shoAving 
that  most  of  the  carbon  has  gone  off  as  carbon  dioxide 
and  carbon  monoxide,  leaving  the  unfused  lime  behind. 
We  can  noAv  start  the  furnace  for  actual  work  and 


344 


IIO:\[F.  AIFCMIAXK^S  FOII  A^F\1M^URS 


four  or  liv(^  ouiu‘(‘s  of  tlu*  cliai^^c'  iii  llu*  arc  as 
soon  as  well  startcMl,  ohscu'viiiu^  llu^  voltin(*t(U’  and  aiii- 
lueter,  if  a study  of  tlie  resistaii(*e  of  furiiaec^  fusions 
is  to  be  made.  The  carbons  ar(‘  drawn  lijradually  a])art, 
and  additional  quantities  of  the  charge  add(*d  from 
time  to  time.  The  cover  is  kept  on  as  mu(‘h  as  possi- 
ble^  only  removing  it  to  add  more  material  and  to  heap 


Fig.  314.  Furnace  for  making  Solders  and  other  Alloys  having 

Low  Melting  Points. 

the  compound  about  tlie  triple  arc  by  means  of  a 
si)atula.  Aft(‘r  a twenty  minutes’  run,  during  which 
tiiiK*  11i(*  compound  is  fr(“<piently  lieaped  about  the 
points  of  lb<‘  (‘l<‘cli()d(‘s,  tlie  switch  may  be  opened 
and  the  furnace*  allowed  1o  cool.  Should  one  of  the 
fuses  blow  out  during  Ihe  run,  it  should  he  immedi- 
ately replac<*d  by  one  of  Ihe  same  cajiacity  and  a small 


HOME  MECHANICS  FOR  AMATEURS 


345 


amount  of  additional  German  silver  wire  added  to  the 
circuit,  although  the  20  feet  of  the  double  material  will 
probably  afford  all  the  protection  necessary  and  steady 
the  arcs  in  a very  satisfactory  manner. 

A variable  rheostat  of  low  resistance  included  in  the 
circuit  would  be  a great  convenience,  allowing  the  cur- 
rent flow  to  be  adjusted  to  the  capacity  of  the  fuse 
wires  to  a nicetv.  A few  runs  with  the  furnace  will 
enable  one  to  become  quite  expert  in  forming  calcium 
carbide,  working  with  a 3-inch  arc  without  allowing  it 
to  go  out.  When  the  furnace  has  cooled,  a number  of 
large  masses  of  the  carbide  will  be  found  in  the  bot- 
tom of  the  fire  brick  hearth,  which  may  he  thrown 
immediately  upon  water  to  obtain  acetylene  gas  or 
stored  away  in  airtight  cans  or  jars  for  future  use.  If 
left  open  in  the  air,  it  is  slowly  attacked  by  moisture 
and  is  decomposed.  Before  suggesting  other  work  for 
small  preparations,  the  introduction  of  a very  small 
crucible  furnace  may  he  of  interest.  Fig.  314  illus- 
trates the  simplest  form  of  crucible  equipment  de- 
signed for  operation  on  the  110-volt  circuit,  Avith  six 
or  eight  32  candle  poAver  lamps  arranged  in  a bridge 
in  multiple  as  indicated.  A large  sand  crucible  or  or- 
dinary floAA'er  pot  is  filled  Avith  granulated  fire  clay  or 
other  poor  conductor  of  heat,  and  a smaller  crucible 
placed  inside.  The  AAdiole  is  stood  on  a fire  brick  and 
the  large  pot  or  crucible  is  provided  Avith  a clay  cover 
having  holes  for  the  reception  of  tAvo  carbon  electrodes. 
The  stands  sold  for  supports  in  chemical  laboratories 
make  the  most  conA^enient  holders  for  the  carbon  rods. 

The  furnace  depicted  in  Fig.  315  is  capable  of  doing 
more  Avork,  in  fact,  as  much  as  may  be  wished  for  on  a 
small  scale,  if  the  experimenter  is  so  situated  that  he 


346 


HOME  MECIIAXICS  EOU  AilATEUES 


may  liave  as  much  cnrront  as  li(>  wants.  Tlie  small 
crucible  is  drilled  tliroufjli  tlie  bottom,  and  one  of  the 
electric  lifi'lit  carbons  c(“m(‘nted  iii  place,  or  sim|)ly  held 
in  position  by  a tight  tit.  The  oiiter  incasement  in 


Fig.  315.  Furnace  for  melting  Brass,  Copper,  etc.,  for  Harder  Alloys, 
and  reducing  Small  Quantities  of  Metallic  Oxides 
to  their  Respective  Metals. 


tills  (lesifi^Ti  (‘OTisists  of  «"i  lar<2;o  floAver  pot,  supported 
on  a small  iron  rinj;-  stand,  also  to  be  had  from  cliemi- 
cnl  (h^aha's.  This  is  covered  by  a heavy  plate  of  mica 
with  a (‘(‘iitral  hoh^  for  tlu^  (*arbon.  I^y  puttin<i^  in 
s(a‘i(*s  two  or  threat  i‘li(M)stats  the  current  may  be  easily 


HOME  MECHANICS  FOR  AMATEURS 


347 


controlled,  and  if  heavy  fuses  are  installed,  and  if 
there  is  no  fear  of  injuring  any  meter,  a very  fierce 
and  intense  arc  may  be  maintained.  Use  only  the  cop- 
pered carbons,  and  solder  their  connections  to  them. 
The  writer  suggests  experimentation  with  alloys,  in 
connection  with  these  small  crucibles  (sand  crucibles, 
plumbago,  or  graphite),  using  borax  in  some  cases  and 
charcoal  in  others  (here  the  light  floury  charcoal  is 
to  be  preferred),  in  order  to  fuse  the  bodies  in  a neutral 
atmosphere. 

By  using  an  excess  of  charcoal  constantly  in  the 
crucible,  the  inert  carbonic  acid  gas  which  is  formed 
will  expel  the  oxygen  from  the  crucible  and  prevent 
oxidation  of  the  metals  experimented  with.  Nearly 
all  the  metallic  oxides  may  be  reduced  in  the  presence 
of  carbon  with  a sufficiently  high  temperature,  provid- 
ing an  interesting  field  for  work.  Small  masses  of 
aluminum  and  aluminum  bronze  may  be  formed  in 
the  crucible  furnace  illustrated  in  Fig.  315,  or  in  the 
large  triple  arc  equipment,  although  only  on  a very 
small  scale.  Aluminum  oxide  (ALOa)  may  be  directly 
reduced  in  the  arc  in  the  presence  of  carbon  by  intro- 
ducing an  intimate  mixture  of  the  oxide  and  poAvdered 
graphite.  The  aluminum  oxide  may  be  bought,  or  may 
be  prepared  on  a very  small  scale  from  clay  or  alum 
as  folloAvs : Digest  8 ounces  of  clay  in  a mixture  of 
hydrochloric  and  sulphuric  acids  in  a glass  flask  (HCl 
3 parts,  H2SO4  1 part)  for  about  an  hour.  The  fluid 
is  mixed  Avith  four  or  five  ounces  of  water  and  filtered. 
An  excess  of  ammonia  (ammonium  hydroxide)  is 
added,  and  the  AAdiite  precipitate  collected  on  a large 
filter  and  alloAved  to  dry.  It  is  then  mixed  Avith  the 
graphite  and  the  tAvo  ground  together.  From  alum,  it 


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IIOMP]  MECIIAXMCS  FOR  AMATEURS 


is  only  JU'(  (‘ssai‘y  to  add  ilic  aniiiionia  to  a stronjj  solu- 
tion of  alnin  in  \vat(‘r,  and  treat  the  r(‘snltant  i)re(ipi- 
tate  in  a like  manner.  Of  eonise  this  ])roeess  is  only 
a little  elieinieal  exercise,  and  is  only  i>iv(*n  for  the 
henetit  of  those  who  wish  to  atteni])t  the  entire  process, 
althon^'h  of  no  commercial  value,  the  manufacture  of 
aluminum  endKxlyiiifi  (“iitirely  nnlik(‘  methods. 

For  the  henetit  of  those  who  have  never  experimented 
with  the  electric  arc,  tlu'  writer  inclmh's  in  the  suj^- 
fi'estions  offered  a pair  of  strongly  smoked  f];lasses,  to 
he  worn  whenever  the  arc  is  exposed.  To  work  with- 
out glasses  is  to  eximse  the  eyes  to  severe  strain  and 
possible  injury. 

RECORDING  TELEGRAPH  FOR  AMATEURS 

If  the  question  of  utility  controls  one  in  making  and 
trying  a piece  of  apparatus,  it  is  useless  to  expect  to 
realize  anything  in  the  way  of  profit  from  the  record- 
ing telegraph  illustrated  and  described;  but  a few  in- 
terested amateurs  can  co-operate,  and  with  a wire  and 
transmitter  for  each  can  secure  a practical  knowledge 
of  the  workings  of  some  of  the  large  telegraph  systems 
and  of  some  of  the  applications  of  electricity,  which 
could  not  be  secured  in  any  other  way.  The  expense 
would  be  slight,  when  there  is  a joining  of  amateurs 
for  one  purpose. 

It  is  assniiK'd  that  an  ordinary  sounder  is  available 
for  the  c<‘ntral  ofiice  recorder,  and  that  every  sub- 
s(‘ri))(‘r  will  fiiriiisli  a transmitter,  a Avire  to  communi- 
cate with  tli(^  (‘(mtral  oftivQ  recorder,  and  battery  snffi- 
ci(ml:  to  oyxa-atc^  one  bran(*h  of  the  centra]  office  system. 

In  makin<»  th(^  (*(mtral  office  recorder,  a common 
soumbn*  is  j)ress(‘d  into  service.  It  is  jmovided  with  a 


HOME  MECHANICS  FOR  AMATEURS  349 


stylus-holder  which  is  clamped  to  the  free  end  of  the 
armature  lever.  The  stylus  is  a piece  of  steel  wire 
1-16  inch  in  diameter  and  1 inch  long,  with  a rounded 
and  hardened  point.  It  is  clamped  in  place  by  a set 
screw. 


Fig.  316. 

The  Receiving  Instrument  of  the  Recording  Telegraph. 

Under  the  free  end  of  the  armature  lever  is  journaled 
an  arbor,  carrying  a wooden  roller  having  a V-shaped 
peripheral  groove  at  the  center,  exactly  under  the 


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IJOMK  MI'XJIIANICS  F()|,>  AMATKUKS 


stylus;  so  that  when  a papcu*  si  rip  passes  over  I lie 
I'oller,  tli(^  stylus  eau  make  a slight  <le])T‘essiou  iu  the 
])apei-,  when  th(‘  soumhu*  majuiiet  is  actuated. 

Th(‘  principal  f(*atur<“s  of  this  tel(*!i>ra])h  are  a sim- 
ple transmitter  for  j>ivin<;  fixed  calls,  like  a call  box, 
and  the  meehanism  for  eaia-yinji  the  jiajim-  taja*  over 
the  f>rooved  sjiool  and  under  the  stylus.  The  roll  of 
tape  as  jmrehasial  from  tin*  dc'aler  is  eariii'd  on  a 
wooden  read,  sujiported  hy  a standard  at  the  rear  of 
the  sounder,  ttetween  two  standards  in  front  of  the 
sounder  are  journaled  two  rollers,  <i  h.  The  roller  a 
is  flanged  and  jirovided  on  its  perijihery  with  three  or 
four  rubber  hands,  to  give  it  frictional  contact  with 
the  paper  tape.  The  lower  roller  h is  covered  with  a 
piece  of  rubber  tube  and  the  shaft  of  this  roller  carries 
a small  governor  c.  for  regulating  the  speed  of  the 
tape.  The  tape  extends  over  the  roller  h,  thence  down- 
ward under  the  flanged  roller  d,  then  upward  to  a 
fastener.  The  roller  d is  ijrovided  with  a weight  which 
actuates  the  mechanism. 

It  will  thus  be  seen  that  the  paper  tape  is  carried 
through  the  machine  by  the  action  of  the  weighted 
roller  d,  and  its  motion  is  regulated  by  the  governor  c. 
The  governor  c consists  of  a slotted  hub  f,  links  g g, 
pivoted  in  the  slots  of  the  hub,  a slotted  sliding  block 
/(,  placed  loosely  on  the  shaft  of  the  roller  h,  weighted 
arms  i i pivotc'd  in  slots  in  the  block  7t,  and  pivotally 
connected  to  the  out(‘r  (*nds  of  the  links  g g,  and  a light 
spring,  j,  tending  to  draw  tin*  weighted  arms  i i toward 
each  olli(‘r.  Tin*  block  It  is  provided  with  a leather 
washer  /,  which  ])roduc<“s  necessary  frictional  contact 
with  the  standai'd,  wlnm  lh(‘  w(‘iglited  arms  are  thrown 
out  by  centrifugal  action.  The  ta])e  reel  is  provided 


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351 


with  a slight  spring  for  checking  its  motion  Avhen  the 
paper  feed  stops.  In  tlie  side  of  the  block  which  car- 
ries the  stylus  is  inserted  a small  stud,  in  which  is 
clamped  a wire  m,  having  its  free  end  near  the  side  of 


the  roller  a,  flattened  and  turned  up  at  right  angles. 
The  flattened  end  of  this  wire  m lies  in  the  path  of  a 
small  pin  projecting  from  the  roller  a,  so  that  when- 


352  HOME  ]\IECITA.\[rS  EOR  A^fATETTRS 


ever  the  aniiatiii'e  lever  is  diawn  down  h_v  (In*  inaj^net, 
the  pin  is  reh'ased,  ajid  tin*  lolha*  a is  allow<“d  to  tnrn, 
hut  when  no  current  passes  tlie  Tnaf>iiet,  the  armature 
lever  rises  and  l)rin<>s  the  fiattfuu'd  (uid  of  tin'  wire  m 
into  th(‘  path  of  tlie  small  pin,  and  sto]>s  tin*  movement 
of  the  I'oller  (i,  and  (•ons(‘(pientl y arr(‘s(s  the  proijress 
of  the  paper,  until  the  ])in  is  r<‘l(>ased  hy  anotlnu’  ac- 
tion of  the  armature  lever,  llindin*-  ]tosfs  i)lac(‘d  at 
the  rear  of  the  sounder  ar('  connected  with  tlu'  ma^^net 
electrically  in  the  usual  way.  To  transmit  a signal 
over  a line  connected  with  this  instrument,  it  is  not 
necessary  to  understand  the  telei>raph  alphabet,  nor  to 
know  anythinji’  in  regard  to  telegraphy.  The  signals 
are  pre-arranged,  so  that  the  operation  of  sending  is 
purely  mechanical. 

The  signal  board  shown  in  detail  in  Fig.  318  was 
invented  and  patented  ^ears  ago  bj"  William  Hadden, 
but  the  patent  has  long  expired.  This  simple  device 
consists  of  a board,  a few  inches  wide,  and  perhaps 
twice  the  length,  depending  on  the  number  and  length 
of  the  messages  sent.  The  board  here  shown  is  inches 
wide,  7 inches  long,  and  f inch  thick,  with  as  many 
longitudinal  grooves  formed  in  it,  as  there  are  signals 
to  be  given.  The  signal  board  must  be  of  very  hard 
wood,  and  the  dots  and  dashes  of  the  signals  are  formed 
by  sewing  No.  30  plain  copper  wire  through  holes  ex- 
tending through  the  board,  from  the  grooves  in  front 
to  the  grooves  in  the  rear.  As  the  signal  transmitter 
is  at  present  constructed,  the  copper  Avire  sewed 
through  th(“  first  s(‘t  of  hob's  represents  the  letters  of 
th(‘  .Morse  alphabc't  from  .1  to  F,  with  a dash  betAveen 
each  letter.  The  sewing  in  the  second  grooA'e  repre- 
sctits  lh(‘  b'iters  from  (i  to  -/.  Tin*  s('wing  in  the  third 


HOME  MECHANICS  FOR  AMATEURS 


353 


groove  represents  the  letters  from  K to  M,  and  so  on. 
All  of  the  wires  forming  these  letters  are  connected 
together  at  the  top  of  the  board,  by  a wire  on  the  back, 
which  is  in  electrical  connection  with  the  binding  post 
seen  to  the  right  in  onr  view  of  the  signal  apparatus. 
The  binding  post  at  the  opposite  edge  of  the  board  is 


Fig.  318.  View  of  the  Transmitting  Apparatus. 

connected  on  the  back  of  the  board  with  a third  bind- 
ing post,  at  the  lower  end  of  the  board.  The  third 
binding  post  is  connected  by  a flexible  cord  with  a 
wire,  having  a flattened  end,  and  provided  with  a 
wooden  handle.  Sending  a signal  consists  simply  in 
drawing  the  flattened  end  of  the  wire  with  a uniform 


354 


IIOMK  MKClIANK.'S  FOIt  AMAI’KUIJS 


si)0(“(l  down  one  of  tlie  grooves.  Tlie  fii-st  two  hinding 
posts,  being  eonneet(‘d  witli  tlie  binding  jiosts  of  the 
reeording  instrnnient  and  with  a batbaw,  wli(*n  a signal 
is  sent,  the  recorder  is  irb'ased  antoniatieally,  and  the 
det(*nt  is  constantly  withdrawn  from  lln*  pin  in  the 
roller,  so  long  as  tin'  signal  is  being  s(‘nt,  and  the  ines- 


Fig.  319.  How  the  Board  is  Wired  for  the  Morse  Alphabet. 

sage  is  thns  recorded.  When  the  signaling  stops,  the 
recoi-ih'i'  is  stopjied  by  the  action  of  the  detent. 

S(!V(‘ral  transmitters  may  be  connected  with  the 
I'ccorder,  and  om*  win*  in  each  case  may  be  dispensed 
with,  by  grounding  the  oth(*r  at  each  end. 

The  record(*r  will  run  long  enough  to  record  a long 
signal  or  sev(‘ral  short  ones  with  one  raising  of  the 
weight  cari'ied  by  the  paper  tape. 


HOME  MECHxVNICS  EOK  AMATEUES 


355 


HOW  TO  MAKE  TELEPHONES  AND  TELE- 
PHONE CALLS 

On  January  30,  1894,  the  Bell  telephone  patent  ex- 
pired and  the  invention  became  the  property  of  the 
public;  so  that  whoever  desires  to  do  so  can  make, 
buy  or  sell  telephones  without  fear  of  infringing  the 


Pig.  320.  Details  of  Construction  of  the  Bell  Telephone. 


rights  of  any  one.  This  applies  only  to  the  hand  in- 
strument now  used  as  a receiver.  Patents  for  other 
telephone  apparatus  still  remain  in  force;  but  enough 
is  available  for  actual  service.  With  two  hand  instru- 
ments and  a suitable  call,  telephonic  communication 
may  be  maintained,  under  favorable  conditions,  over 


356 


HOME  MECHANICS  FOR  AMA'l'EUlJS 


a line  eight  or  ten  miles  long,  no  battery  being  re- 
quired. 

To  avoid  the  effects  of  indnetion  and  to  secure  the 
best  results,  a metallic  circuit  is  re(iuired.  It  lias  been 
said,  on  good  authority,  that  with  band  telephones 
used  as  transmitter  and  receiver,  conversation  has 
been  carried  on  between  New  York  and  Chicago,  using 
a metallic  circuit  formed  of  heavy  copper  wire  and 
having  very  low  resistance.  The  words,  it  is  said, 
were  as  distinct  as  where  a transmitter  is  used,  hut  the 
volume  of  sound  Avas  somewhat  less. 

For  the  benefit  of  those  who  are  desirous  of  making 
telephones  for  their  own  use,  or  for  sale,  we  present 
perspectiA'e  and  sectional  views  of  the  latest  and  most 
improved  form  of  telephone,  all  of  the  parts  of  which 
are  shown  in  reduced  size. 

The  handle  is  made  of  hard  rubber  and  the  cap, 
which  is  also  the  mouthpiece,  is  of  hard  rubber.  The 
diaphragm.  A,  is  clamped  at  the  edge  between  the  cap 
or  mouthpiece  and  the  body  of  the  handle.  Very  thin 
ferrotype  plate  has  generally  been  used  for  the  dia- 
phragm, but  thin  taggers  iron,  Avhen  protected  by  a 
coat  of  shellac  or  other  suitable  varnish,  is  said  to  an- 
swer better. 

The  compound  magnet,  R,  used  in  the  telephone,  is 
com]K)sed  of  four  thin,  flat  bar  magnets,  a,  arranged 
in  pairs  on  ojiposite  sides  of  the  flat  end  of  the  soft  iron 
pole  i)i(‘ce,  c,  at  one  end,  and  the  soft  iron  distance 
])icc<‘,  d,  at  the  opposite  end,  the  magnets  being 
clamix'd  to  flu'se  ])i(“c(‘S,  with  like  poles  all  in  one  di- 
recfion.  Tin*  space  in  fhe  center  of  the  magnet  be- 
f \\(‘en  th(^  ])oi(‘  ]»i<‘ce  and  distance  piece  is  filled  Avith  a 
sti-i]),  <!,  of  Avood. 


HOME  MECHANICS  FOR  AilATEURS 


357 


The  fj’lindrieal  end  of  the  distance  piece  which  ex- 
tends beyond  the  magnet  is  bored  and  tapped  to  re- 
ceive the  screw  by  which  the  magnet  is  held  in  place 
in  the  handle.  The  cylindrical  projecting  end  of  the 
pole  piece  extends  to  within  1-100  or  2-100  of  an  inch  of 
the  diaphragm.  In  other  words,  it  is  placed  as  near  the 
diaphragm  as  possible  without  being  touched  by  the 
diaphragm  when  the  latter  vibrates. 

On  the  pole  piece,  c,  is  placed  a wooden  spool,  c,  on 
Avhich  is  wound  No.  34  (Am.  W.  G.)  silk-covered  cop- 
per wire.  The  wire  tills  the  spool,  and  its  ends  are  al- 
lowed to  project  one  or  two  inches.  The  wire  may  be 
Avound  on  the  spool  in  either  direction,  and  it  is  im- 
material Avhich  pole  of  the  compound  magnet  adjoins 
the  diaphragm. 

The  resistance  of  the  winding  varies  from  70  ohms 
as  a minimum  to  200  as  a maximum.  When  the  in- 
strument is  to  be  used  both  as  transmitter  and  receiver, 
and  especially  Avhen  it  is  on  long  lines,  the  resistance 
should  be  100  ohms  or  more.  No.  36  wire  is  used  for 
the  winding  Avhere  the  resistance  is  great.  Of  No.  34 
wire,  263  feet  Avill  be  required  for  70  ohms  resistance. 
For  100  olnns,  373  feet  are  required.  For  150  ohms, 
343  feet  of  No.  36  are  required. 

In  the  end  of  the  handle  are  inserted  two  binding 
posts,  to  which  are  attached  insulated  Avires  (No.  18), 
Avhich  extend  toward  the  diaphragm,  their  free  ends 
being  soldered  to  the  terminals  of  the  fine  wire  on  the 
spool,  so  that  when  the  telephone  is  connected  up  in 
circuit  Avith  other  telephones  the  current  Avill  pass  from 
one  of  the  binding  posts  through  one  of  the  coarse 
wires,  through  the  fine  Avire  coil,  through  the  other 
coarse  wire  to  the  other  binding  post. 


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TTOME  MECHANICS  I’OIi  AMA'I’CriJS 


Tlie  Hell  teleplione  lias  a disk  of  di'xilili*  iMiblior 
sli])])ed  over  tlie  jiole  piece  and  over  the  ends  of  the 
coarse  wires  as  a jiiiard  ajjainst  shoi-t  circuit  in, <>■.  A 
screw  eje  is  inserted  in  the  end  of  the  telephone  handle 
for  suspendiiii?  the  instmiinnit  when  not  in  nse. 

This  telephone,  when  used  in  the  manner  sn''\<iest(“d, 
requires  neither  hatterv  nor  induction  coil.  It  is 
therefore  easily  connected  up  for  use  hy  electrically 
connectini*’  the  binding  posts  of  one  instrument  with 
the  binding  posts  of  another.  Wlnm  a number  of  tele- 
phones are  connected  in  the  same  lim*,  the  niatt(*r 


Fig.  321.  Fio.  322. 

Single  Wire  Circuit. 


is  not  quite  so  simple.  There  are  many  ways  of  ar- 
ranging the  circuit;  we  give  diagrams  of  two,  one  for 
one  line  wire  with  ground  connections,  the  other  for 
a metallic  circuit,  Avith  a separate  circuit  for  calling. 

In  lh(‘  single  wire  circuit  each  instrument  on  the  line 
is  pi-ovidt'd  with  a double  switch  cut  into  the  line  as 
shown  in  Fig.  ;i21,lh<‘  ])ivots  of  the  switch  arm  a a',  be- 
iim  conn(“cted  with  the  line  wire.  The  switch  arms 
are  jiivolally  connecl(‘d  with  a bar  of  insnlating  mate- 
rial, so  I hat  they  will  mov(‘  to,g(‘lher.  The  arms,  <i  o', 
may  be  bi-onghi  inlo  coidact  with  the  ])oints,  d.  <V . e. 


HOME  MECHANICS  FOR  AMATEURS 


359 


e',  and  f.  A magneto  call  box  is  connected  with  the 
points,  d d' , and  the  arms,  a a' , are  left  normally  on 
these  points,  as  shown  in  dotted  lines,  so  that  when 
any  magneto  in  the  line  is  operated  the  others  will 
ring.  All  on  the  circuit  have  a special  call. 

The  one  called  will  know  whether  the  signal  comes 
from  the  east,  west,  north  or  south.  Suppose  it  to 
come  from  the  east,  the  switch  is  placed  in  the  position 
shoAvn  in  full  lines.  This  cuts  out  the  magnetos, 
grounds  the  western  section  of  the  line  through  the 
point,  c,  and  connects  the  eastern  section  with  one 


Fig.  323.  Metallic  Circuit. 


end  of  the  telephone  cord  through  the  point,  c',  the 
other  telephone  connection  being  grounded  through 
the  points,  f c,  and  ground  wire.  If  the  call  is  from 
the  west,  the  switch  arms,  a a' , are  brought  into  con- 
tact with  the  points,  e'  f.  The  arms,  a a',  are  always 
left  on  the  points,  d,  d'.  Outside  the  terminal  stations 
the  line  is  connected  with  the  ground  or  arranged  as 
shown  in  Fig.  322,  with  the  line  grounded  through  the 
magneto  or  telephone. 

In  the  metallic  circuit  shown  in  Fig.  323,  the  termi- 
nal telephones  are  connected  with  the  ends  of  the  line 


360 


HOME  ]\IP:CHANICS  for  AMATFUIiS 


wires.  Intermediate  tcdepliones  are  cut  into  the  line 
bj  means  of  a double  switcli,  as  shown  in  the  cut,  in 
Avbich  (j  shows  the  intermediate  telephone  cut  out,  h 
shows  it  connected  with  the  east  and  i with  the  west. 

A third  Avire  grounded  at  the  ends,  and  including?  a 
magneto  for  each  tele])hone,  runs  parallel  with  the 
metallic  circuit.  In  this  case  all  of  the  hells  ring  at 
once,  and  individual  signals  must  he  agreed  upon. 

It  is  obvious  that  the  information  here  given  in  re- 
gard to  the  construction  of  the  telephone  may  he  de- 
parted from  in  minor  points,  such  as  the  construction 
of  the  handle  and  mouthpiece,  hut  eA’erything  relating 
to  the  magnet,  the  coil,  and  the  relation  of  the  magnet 
and  diaphragm,  should  he  strictly  followed. 

No  telephone  line  is  complete  without  a signal  of 
some  kind  which  will  serve  to  attract  the  attention  of 
a person  in  the  Aucinity  of  the  instrument.  A battery 
call  ansAA’ers  A’ery  Avell  for  short  distances,  but  for  a dis- 
tance of  from  one  to  tAvelve  miles  or  more,  the  battery 
has  been  found  impracticable  and  the  magneto  call  is 
generally  employed.  This  instrument  not  only  serves 
a good  purpose  in  connection  with  the  telephone,  hut 
it  answers  very  Avell  indeed  for  general  signaling  pur- 
poses. It  is  always  ready  for  action,  and  does  not  in- 
volve the  care  of  a battery. 

The  line  draAvings  presented  herewith  are  one-third 
the  actual  size  (linear  measurement)  of  the  instru- 
ment, and  the  persjx'ctive  vicnv  is  also  one-third  of  the 
actual  size;  the  oidy  dimension  not  obtainable  from 
the  di-a wings  is  tlie  d(“i)th  of  tlu'  signal  box,  which  is  3 
inches.  As  all  of  the  dimensions  may  he  obtained  from 
the  eugraviugs,  it  Avill  he  unnecessary  to  repeat  them 
in  th(Mlescri])tive  matter. 


HOME  MECHANICS  FOR  AMATEURS 


301 


The  pole  pieces,  A A',  between  which  armature,  B, 
revolves,  are  formed  of  soft  gray  cast  iron,  with  ears, 
a a,  at  the  top  and  the  ears,  h,  at  the  bottom,  separat- 
ed by  bars,  C C',  of  nou-magnetic  material,  such  as  vul- 
canized fiber,  hard  rubber,  or  they  may  be  made  from 
hard  wood,  well  varnished  or  saturated  with  paraffine 
to  prevent  them  from  shrinking  or  swelling.  The  pole 
pieces,  A A',  are  clamped  to  the  bars,  C C',  before  they 
are  bored  out.  The3"  are  bored  out  to  loosely  fit  the 


Fig.  324.  Magneto-Telephone  Call. 


armature,  R'.  The  pole  pieces  are  provided  with  fianges, 
c,  which  rest  upon  the  bottom  of  the  casing  and  are 
drilled  to  receive  screws,  d,  by  means  of  which  the  mag- 


IIOMK  MKCMIANK^S  FOR  \^\\TVAl\l^ 


ii(‘i  is  S(‘(*iir(Ml  in  ])la('(‘  in  ili(‘  ('asini^.  In  lln*  ]K)1(‘  ])i(*c(*s, 
A A',  al)()V(‘  tli(‘  (‘ars,  />,  ai'(^  diallcMl  and  ta])i)(*d  liol(*s,  r, 
for  r(M*(Mvini>’  tli(‘  studs,  /,  l)y  wliirli  tln^  li()rs(‘sli()(‘  inaiL>^- 
nots  ar(^  secured  lo  tlu^  ])ol(‘  ])i(‘(‘(*s.  Th(‘  studs,  /,  ai'(^ 
drilled  for  re(‘eivini>  keys,  by  wliieli  tlie  nny^nets  are 
clamped  in  ])la(*e. 

The  ('oniponnd  niai^net,  2,  is  com])ns(Ml  of  three  Hat 
steel  bars  foiininji^-  r-shap(Ml  nia<;n(ds,  //,  //',  //%  with 
the  space  between  the  ])oles  ada])ted  to  receive  the  pole 
])ieces,  A A'.  The  ina<>net  Ir^  tits  over  tlu^  adjoinin^i;- 
ed!L>es  of  the  nia<>‘nets,  li  //',  and  the  three  inai»n(ds  are 
drilled  to  receive  the  studs,  /,  which  (‘xtend  thi-ongh 
the  niaf>nets  and  into  the  ])ole  })ieces,  the  parts  Ixdng 
clamped  together  by  keys  driven  throngh  the  holes  in 
the  stnds,  as  shown  in  the  perspective  view. 

The  armatnre,  R,  is  the  Avell  known  II  type  of  Sie- 
mens, made  of  soft  gray  cast  iron,  the  sliaft,  being 
cast  integrally  Avith  the  body  of  the  armatnre.  The 
part,  j,  which  receives  the  Avire  is  narroAA  er  and  shorter 
than  the  polar  extremities  of  the  armature.  The  arma- 
ture is  turned  so  that  its  convex  sides  will  revoh^e  very 
near  but  not  in  contact  Avitli  the  pole  pieces.  The 
shaft  at  the  ends  of  the  armature  is  turned,  and  to  one 
end  is  fitted  a sleeA^e,  k,  of  insulating  material  (vul- 
canizcMl  fil)er  or  hard  rubber),  on  Avhich  is  placed  a 
l)rass  i‘ing,  1.  In  the  inner  side  of  the  metallic  ring, 
is  insei-tcal  a stud,  n,  to  Avhich  is  soldered  one  terminal 
of  1h(*  ai'inaturc^  coil,  the  other  terminal  of  Avhich  is 
sobhaxxl  1o  a scr(‘w,  ii,  inscaded  in  the  shaft,  i.  The 
arnialni‘(‘  is  wound  in  th(‘  sann^  manner  as  an  electro- 
niagmd,  I In*  wir(‘  b(*ing  carri(xl  around  om^  arm  of  the 
araaalnrc*  nnlil  on(*-half  of  tln^  Avirc^  is  in  pla(*e.  It  is 
llnm  car]‘i(*d  across  th(‘  c(ai(ral  portion  of  llu^  anna- 


HOME  MECHANICS  FOR  AMATEURS 


363 


ture  and  wound  upon  the  other  arm  of  the  armature. 
The  wire  used  is  No.  34  silk-covered  wire,  there  being 
about  14  ounces  of  wire  upon  the  armature,  or  enough 
to  give  it  a resistance  of  200  ohms. 


To  the  bar,  C,  is  secured  a brass  plate,  E,  by  means 
of  screws  which  pass  througli  the  plate  and  into  the 
bar.  In  the  plate,  E,  opposite  the  center  of  the  bore  of 
tlie  pole  pieces,  there  is  a bearing  for  one  end  of  the 
shaft  of  the  armature,  and  in  the  opposite  or  upper  end 


3G4 


ll():\II-:  MKCIIAAMCS  F()l{  AJIATJ<:UI{S 


<»f  I lie  brass  plaii*,  E,  (lua  e is  a bearin'^  for  ibe  (Iriviiifi; 
shaft,  b\  To  flu*  ojijiosite  end  of  tlie  bar,  C,  and  to 
the  bar,  V/,  is  seenred  a ])lat(‘,  E',  wliicli  is  also  jiro- 
A'ided  witli  b(*arinos  for  tlie  armature  shaft  and  for 
the  drivinij  shaft.  To  tlie  bar,  C,  is  seenred  a curved 
spi-inji;,  e,  wliicb  boars  uiion  the  insulated  rlufj,  ?,  and 
this  sprinjj  is  connected  by  a wire,  />,  Avitli  a binding 
])ost,  q,  at  the  top  of  the  casing. 

ITpon  the  end  of  the  armature  shaft,  i,  outside  the 
plate,  E',  is  jdaced  a pinion,  r,  and  upon  the  shaft,  F, 
is  placed  a spur  wheel,  .s,  which  engages  the  pinion,  r. 
The  shaft,  F,  is  held  in  place  in  the  machine  by  a screw 
inserted  in  the  end  of  the  shaft,  and  a washer  held  by 
the  screw  against  the  end  of  the  shaft  and  bearing 
against  the  plate,  E.  The  crank,  C,  by  which  the  shaft, 
F,  is  turned,  is  screwed  on  to  the  end  of  the  shaft 
through  an  aperture  in  the  side  of  the  casing.  On 
the  stud,  f , projecting  through  the  front  of  the  magnet 
is  placed  a contact  spring,  t,  which  is  clamped  by  the 
key  which  holds  the  magnet  in  place. 

The  mechanism  thus  described  comprises  the  mag- 
neto generator  which  generates  the  alternating  cur- 
rent reipiired  for  operating  the  magneto  bell.  The 
machine  is  held  in  place  in  the  casing  by  the  screws, 
(1.  as  already  described,  and  the  back  of  the  casing  is 
cut  away  to  let  the  magnet,  into  the  back,  thus 
( conomizing  room.  To  the  cover  of  the  casing  is  at- 
<acli(‘d  the  magneto  ladl,  11,  the  magnet  and  armature 
of  which  ar(‘  placed  within  the  door,  Avhile  the  bells 
are  jilaced  on  tin*  outside  of  tin*  door,  the  hammer  ex- 
t(‘nding  tbrongb  (he  door  and  between  the  bells. 

The  body  of  tli<‘  magiK'to  call  consists  of  a curved 
casting,  u,  wbicli  is  secured  to  the  inner  face  of  the 


HOME  MECHx\NICS  FOR  xVMATEURS 


365 


door  and  provided  with  loops,  v v' , for  receiving  the 
soft  iron  pole  pieces,  w w',  of  the  bell  magnet.  These 
pole  pieces  are  held  in  place  in  the  loops,  v v',  by 
screws  passing  through  the  side  of  the  loop  and  bear- 
ing against  the  pole  piece.  The  convex  side  of  the 
casting,  u,  is  provided  with  a rectangular  notch,  a’, 
for  receiving  the  L-shaped  permanent  magnet,  6',  which 
is  held  in  its  place  by  a screw  passing  through  the 


Fig.  326.  Details  of  Magneto-Call — the  Bell. 


magnet  into  the  casting.  To  the  L-shaped  magnet,  h', 
is  secured  a plate,  c,  which  is  bent  twice  at  right 
angles,  and  in  the  bent  ends  of  which  are  inserted  pivot 
screws  supporting  the  armature,  cl,  which  extends 
downward  between  the  adjacent  ends  of  the  pole  pieces, 
iv  tv'.  The  armature  is  covered  by  a strip,  e',  of  cop- 
per, and  in  the  end  of  the  armature  is  inserted  a wire, 


3G6 


TIOMIO  MECHANICS  FOI{  AMATI0U1?S 


/,  carrying  at  its  cxirciiiity  a Ix'll  liamiiicr,  </'.  To  tlio 
outer  surface  of  tlie  door,  and  ou  o])])osit(*  sides  of  tlie 
bell  liauiuier,  are  sup])orted  two  bells,  I,  by  studs,  i', 
])rojectiug  from  adjustable*  jelates,  /,  ])ivoted  to  the 
door  at  one  end  and  ])i-ovid(*d  wilb  a curved  slot  at  the 
opposite  cud  for  receiving  a claiu])iug  screw,  wliicb 
passes  tbrougb  tin*  slot  and  into  tin*  door.  liy  means 
of  this  device  the  bells  may  be  adjusted  so  that  each 
will  receive  a stroke  of  the  same  power  from  the  bell 
hammer,  //'. 

The  spools  ou  the  ])ole  piece's,  tc  ir',  emutain  abeeut 
lA  ounces  of  Nee.  34  silk-ce)ve*)'(*et  e-opper  wire.  They 
are  wouuel  iii  the  same  dirce-tieeu,  and  the  inside  ends 
are  connected  together.  The  eenter  end  of  eene  spool 
is  connected  with  the  upper  hinge  of  the  casing,  which, 
in  turn,  is  connected  with  the  binding  post,  (/ ; the 
outer  end  of  the  remaining  spool  is  connected  with  a 
strip,  of  copper  attached  to  the  door  and  connected 
with  a plate,  which  conies  into  contact  Avith  the 
spring,  t,  Avhen  the  door  of  the  casing  is  closed. 

On  the  tojA  of  the  casing  there  is  a plug  switch, 
Avhich  also  answers  as  a lightning  arrester.  The  rear 
plate  of  the  SAvitch  is  provided  Avith  the  binding  post, 
'HI,  Avhich  is  connected  Avith  the  ground.  The  binding 
posts,  (j  (/,  receiA’e  the  ends  of  the  line  wire,  the  con- 
nections being  made  as  shoAAm  in  the  section  on  the 
teleyihone,  pages  358-800. 

When  the  call  is  placed  at  the  end  of  the  line  the 
call  box  is  grounded  by  inserting  the  ping,  r,  betAveen 
tin*  rear  or  ground  ]date  and  the  front  ]>late  that  is 
not  connected  Avith  a line  Aviri*.  When  it  is  desired  to 
cut  tin*  call  box  out  of  tin*  line,  the  plug  is  inserted  in 
the  circular  spaci*  betw('(*n  the  two  front  plates,  the 


HOME  MECHANICS  FOR  AMATEURS  367 


current  passing  from  one  end  of  the  line  through  one 
of  the  binding  post  to  the  other  portion  of  the  line. 
When  the  armature,  B,  is  turned  by  revolving  the 
crank,  G,  opposite  ends  are  alternately  presented  to 
opposite  poles,  the  consequence,  being  that  the  rapid 
changes  of  magnetism  in  the  armature  induce  alter- 
nate pulsations  in  the  winding  of  the  armature  which 
operate  the  polarized  bell  of  the  instrument,  also  the 
polarized  bell  of  the  distant  instrument,  both  being 
normally  in  the  circuit. 

While  talking  over  the  line  it  is  important  to  cut 
out  the  magnet  on  account  of  its  resistance,  and  while 
signaling  over  long  distances  the  signals  are  more 
effective  if  the  telephones  are  cut  out  of  the  line. 

These  machines  can  be  purchased  for  |4,  and  we 
therefore  doubt  if  it  is  profitable  to  undertake  to  make 
them ; however,  they  may  be  made  without  fear  of  legal 
complications,  as  they  are  not  patented. 


THE  END. 


% 


« 


T N I)  E X 


Barometer  201 

Bas-Reliefs  69 

Battery,  Primary  227 

Brass,  Burnished  78 


Cabinet,  Electrical  246 

Cabinet,  Wall  40 

Caloric  Engine  176 

Carving,  Wood  26 

Centering  106 

Chasing  126 

Chime,  Electric  237 

Chucking 112 

Cutters,  Rotary  136 


D 

Brills  and  Drilling  99 

Dynamo,  Edison  319 


E 

Electricity  227-367 

Electric  Lighting  232 

Engines  and  Boilers,  Model, 

169-184 

Engines,  Running  175 


Pace 

Fluted  Work,  Turning  ....  10 


Frames  36 

Furnace,  Electric  333 

G 

Gear  Cutting  152 

Glass,  Stained  51 

Grilles  and  Gratings  31 


Grinding  and  Polishing  . . 92 


H 

Household  Ornaments  ....  31 

Hygroscope  198 

I 

Index  Plates 147 

Iron  Work  73 

K 

Knives,  Moulding  9 

Knurling  126 


L 

Lamp,  Electric  Night  ....  243 
I^aimch  Motor,  Electric...  298 

Lathe,  Foot 96 

Lathe,  Inexpensive 1-7 

Lathe,  Woodworking  on  a.  8 


Majolica,  Imitation  49 

Metal  Turning? 119 

Metal  Working 89-1  98 

Meteorology  187-205 

Microscoi)e,  The  218 

Model  Making  155 

Motor,  Edison  319 

Motor,  Sewing  Machine  . . 278 
Motor,  Simple  Electric  . . . 259 
Motor,  Small  Electric  ....  270 

Moulding  Knives  9 

Moulding,  Wood  11 

O 

Ornament,  Feather  39 

Ornaments,  Household  ...  31 


P 

Plaster  Objects  85 

Portiere  57 

Pseudo-Ceramics  41 

R 

Rain  Gauge  193 

Repousse  61 


S 

Sawing,  A Wrinkle  in  ...  . 25 


Sawing  Metals  89 

Saw,  Scroll  12 

Saw  Tooth  21 

Saw,  Wood  8 


Scroll  Snw  

Pack 

12 

; Silver  Work  

94 

Slide  Rest  

Soldering  

90 

Spinning  Metals  . 

160 

Stained  Glass  . . . 

51 

Steadving  

106 

Steam  Engine  . . . 

169 

T 

Telegraph,  Recording  ....  348 

Telephone,  How  to 

Make.  . 355 

Telescope,  How  to 

Make...  207 

Telescopes  and 

Micro- 

scopes  

207-225 

Thermometers  . . . 

194 

Tooth,  Saw  

21 

Turning,  Wood  . . 

6 

V 

Vases  

41 

W 

Wall  Ornaments  . . 

35 

Water  Motor  

181 

Weather  Vane  . . . . 

189 

WGiittling  

16 

Wind  Pressure  Gauge  ....  190 

Wire,  Things  in  . . 

75 

Wood  Carving  . . . . 

26 

Wood  Turning  . . . . 

6 

Wood-Working  . . . 

1-29 

Work  Bench 

14 

Tools  for  Home  Mechanics 


—13 
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